﴾ By the dawn* By the ten nights (i.e. the first ten days of the month of Dhul-Hijjah), ﴿

[ Al-Fajr, 1-2 ]

This Divine Oath alone makes these days the best of days in the Muslim's life, for the Great (i.e. Allah) does not swear but by something great…

﴾ By the dawn* By the ten nights (i.e. the first ten days of the month of Dhul-Hijjah), ﴿

[ Al-Fajr, 1-2 ]

This entails that Muslim should pay the best of his efforts during these ten days, should offer good deeds abundantly, should welcome these days properly and should  use this opportunity well. 
This is the topic of this lecture, and it is the most befitting one since we are about to welcome these ten days. Scholars said, "What should the Muslim do to welcome these days? He should turn to Allah with sincere repentance." In fact, this is what the believer does  abundantly on religious occasions like this one;  he starts  major acts of worship (like Ramadan or Hajj) with sincere repentance. Allah says:

﴾ O you who believe! Turn to Allah with sincere repentance! ﴿

[ At-Tahrim, 8 ]

In another Ayah, Allah says:

﴾ And all of you beg Allah to forgive you all, O believers, that you may be successful. ﴿

[ An-Nur, 31 ]

As you all know, repentance entails religious knowledge, physiological status,  and action. The more you educate yourself religiously, the better you will realize your sins, and when you realize your sins, you will be severely regretful. This knowledge and remorse will make you abandon whatever sin you commit  immediately, determine not to do it again in the future and finally correct your previous sins. Hence, repentance entails abandoning, determination, and rectifying sins, which are preceded by remorse and knowledge.

  How should we welcome these blessed days?

  I will mention in a while some Prophetic As7adeth in which the virtues of these ten days are mentioned. The Muslim should receive these days with strong determination to make use of them, should make the performance of the acts of worship perfect, should increase his good deeds and should apply the Sunnah the  scholars deduced from the Noble As7adeth concerning these days. Allah says:

﴾ As for those who strive hard in Us (Our Cause), We will surely guide them to Our Paths (i.e. Allah's Religion - Islamic Monotheism). ﴿

[ Al-Ankabut, 69 ]

The second thing, the Muslim should do during these days is to stay away from sins. One might say, "Well, this is a habitual activity in Muslim's daily life," and yes this is true, but as for those who fall in sins, they should abandon their sins, those who are thinking about sinning, they should perish any thoughts of this kind and those who already repented from their sins, they should stay steadfast in abandoning them.
There is a rule that goes as follows, when the striver is ordered to strive, this means that he should stay steadfast on his striving. Regarding this point, pay attention to the following Ayah, in which  Allah asks his Prophet to keep his duty to Him: 

﴾ O Prophet (Muhammad PBUH)! Keep your duty to Allah ﴿

[ Al-Ahzab, 1 ]

Does this request mean that the Prophet PBUH did not keep his duty to Allah? Of course not, for he had already kept his duty to Allah, but this request means to stay determined and steadfast on his piousness.
Dear brothers, scholars said, "Obeying Allah's Orders draws someone close to Allah the Almighty, while sins drive him away from Allah." Hence, obedience draws the Muslim close to Allah, while sins drive him away from Allah, a good deed might be the reason to approach Allah, while a bad one might be the reason of being veiled from Allah and a deed makes you reach Allah, while another deed might severe your ties with Allah. 
Actually, the true believer is very keen on offering every deed that brings him closer to Allah, and he is very keen on staying away from any deed that drives him away from Allah. Man might be deprived of Allah's Mercy because of a sin he committed, so whoever is keen on reaching Allah should obey Him and offer good deeds. Allah says:

﴾ So whoever hopes for the Meeting with his Lord, let him work righteousness and associate none as a partner in the worship of his Lord." ﴿

[ Al-Kahf, 110 ]

Hence, we should receive these ten days by turning to Allah with sincere repentance. Let me ask you this question, what are the acts of worship around the year that should be performed? The Muslim should offer Fajr within its time, he should reauthor the Quran daily, he should reflect on the creation of the heavens and the earth and he should invoke Allah. Hence, the acts that should be done around the year are remembrance of Allah, invoking Him, pondering over His Creations, reciting the Quran and offering Salah.
There must be a daily period of time (all year long), whether during the day or the night or before sunrise or sunset, during which the Muslim establishes a connection with Allah the Almighty, so this period of time should be an intensive course  during these ten days, given the acts of worship are the reasons of being close to Allah, whereas sins are the reasons of being driven away from Allah. 

Virtues of those ten days as mentioned in the Noble Quran:

  What are the virtues of the ten days of Dhul-Hijjah according to the Noble Quran? The following Ayah  indicates these virtues.  Allah says:

﴾ By the dawn; By the ten nights (i.e. the first ten days of the month of Dhul-Hijjah), ﴿

[ Al-Fajr, 1-2 ]

The ten nights according to some Quran interpreters are the first ten days of Dhul-Hijjah, and this is agreed upon by scholars of interpretation, the pious ancestors and the pious successors. There is another Ayah which denotes, according to scholars, these ten days. Allah says:

﴾ And mention the Name of Allah on appointed days (i.e. 10th, 11th, 12th, and 13th day of Dhul-Hijjah), over the beast of cattle that He has provided for them (for sacrifice) (at the time of their slaughtering by saying: Bismillah, Wallahu-Akbar, Allahumma Minka wa Ilaik). ﴿

[ Al-Hajj, 28 ]

The majority of scholars agreed that the above-mentioned Ayah refers to the first ten days of Dhul-Hijjah. 

(( It was Narrated by Jaber that the Prophet, prayers and peace of Allah be upon Him, said: "The best days of the worldly life are the ten days - meaning the ten nights of Dhul-Hijjah- It was said: "Are not they like fighting for the sake of Allah?" He PBUH said: "No, except for a man whose face was covered with dust striving for the Cause of Allah." ))

[ Reported by Al-Bazzar from Jabir ]

What if these ten days were spent in striving in the Cause of Allah, fighting Islam's enemies and sacrificing the worthy and the cheap? The Prophet PBUH said:

(( "Are not they like fighting for the sake of Allah?" He PBUH said: "No, except for a man whose face was covered with dust striving for the Cause of Allah." ))

Pay attention to the fact that the Prophet PBUH does not speak of his own desire…

﴾ It is only an Inspiration that is inspired ﴿

[ An-Najm, 4 ]

The words of the Prophet PBUH are non-reauthord revelation:

(( "The best days of the worldly life are the ten days - meaning the ten nights of Dhul-Hijjah- It was said: "Are not they like fighting for the sake of Allah?" He PBUH said: "No, except for a man whose face was covered with dust striving for the Cause of Allah." ))

[ Reported by Al-Bazzar by Jabir ]

This leads us to say that the Hujjaj (pilgrims) are in the focus point of the Divine Whiffs, while those who are not Hujjaj are hovering over this focus point. In other words,  the Divine Gifts are granted to the sincere Hujjaj on the day of Arafah (the day where the Hujjaj stand at Arafah Mount). It is the best day ever; the day when the sincere Hujjaj, are forgiven, are freed  from Hellfire, are divinely Accepted and are Divinely Honored. Not to mention, they come back from Hajj as if they were born today.  Satan has never been so desperate more than he is on Arafah day, because Allah forgives those Hujjaj at Arafah, accepts them and forgives them, and He is pleased with them. Regarding those who are not Hujjaj,  they are recommended to strive hard on these ten days to have some of these Divine Gifts. It is reported that, "Whoever stands at Arafat, but he is not  sure that all their sins will be forgiven, his Hajj will be rejected." 
I would like to repeat this point. Hujjaj are in this focus point of Divine Gifts, whereas those who are not Hujjaj should hover over this focus point. Hence, the one who does not have the chance to offer Hajj should make use of this opportunity on these ten days and strive hard to draw close to Allah the Almighty by performing extra acts of worship, by distinctively donating, by abundantly performing good deeds and by learning more about Islam. Also, among the things that indicate the virtues of these ten days Arafah Day, which is described as the day of the Major Hajj (Al-Hajj Al-Akbar); it is the day of forgiving sins and  freeing Hujjaj from Hellfire. Had Arafah Day been the only day of the ten days of Dhul-Hijjah, it  would have been enough virtue.
By Allah dear brother, what deserves to offer your congratulations to someone from the bottom of your heart is to see him reconciling with Allah. You may congratulate someone for buying a beautiful and a spacious and luxurious house, which has a beautiful view, but will the owner live in his house forever?  No, he will not, because one day he will leave this house lying in a casket without coming back, so will each one of us.
When one of us is alive, his family gets worried about him upon staying out till a late hour, and they start asking about his whereabouts, whereas the deceased will not be worried about, and his family will not wonder when he will come back home, because he leaves the house  for good.
I repeat: it is enough virtue in  these ten days of Dhul-Hijjah that Arafah Day is one of them. As for you, as a Muslim, you should congratulate someone for reconciling with Allah, as it is the kind of congratulation that matters, because you are congratulating him for knowing Allah, for obeying Him and for offering good deeds. This is what really counts, while  congratulating someone for buying a house, for having a successful business, for getting a scientific degree or for occupying an important position, does not benefit him, since these things  are evanescent.

The foremost acts of worship are offered in these days:

  Among  the virtues of these ten days is  the Day of Nahr (the day of sacrifice). According to the following Hadith, this is one of the best days of the year:

﴾ The greatest day in Allah's Sight is the day of sacrifice. ﴿

[ Ahmad, Abu Dawood and Al-Hakim by Abdullah bin Qart ]

There are so many symbols in our life, such like the flag which has four colors (red, black, green and white), so if this flag is undermined by someone, he will be severely punished, and if he says, "It is just a piece of fabric", we say, "No, it is not. It is an important symbol of your country." Every country has its own sacred symbols. Much in the same line, the day of sacrifice (The day of Nahr) stands for something more sacred than just slaughtering the animal; it symbolically means slaughtering the forbidden desires and man's  yearn for sins. Thus, it is the day when the Muslim reconciles with Allah in slaughtering his lusts which displease Allah the Almighty. The day of Nahr is also one of the first ten days of Dhul-Hijjah. 
Al-Hafiz bin Hijr (a very notable scholar) said in Fath Al-Bari in Interpreting Sahih Al-Bukhari, "The most apparent reason for the ten days of Dhu'l-Hijjah being distinguished in excellence is due to the assembly of the greatest acts of worship in this period, i.e. salawat (prayers), siyam (fasting), sadaqah (charity) and the Hajj (pilgrimage). In no other periods do these great deeds combine."

 The first ten days of Duhl-Hijjah are the best days in  Muslim's life:

Dear brothers, you are about to receive these ten days:

(( Narrated Ibn 'Abbas: The Prophet (PBUH) said, "No good deeds done on other days are superior to those done on these (first ten days of Dhul Hijja)." Then some companions of the Prophet (PBUH) said, "Not even Jihad?" He replied, "Not even Jihad, except that of a man who does it by putting himself and his property in danger (for Allah's sake) and does not return with any of those things." ))

[ Al-Bukhari by Ibn Abbas ]

He does not return with anything, because  he sacrifices his property and life for the Sake of Allah. 

(( Narrated Abdullah Ibn Umar, may Allah be pleased with both of them, he said: I was once with the Prophet PBUH and I asked about the best of deeds to which he said: "No good deeds done on other days are superior to those done on these (first ten days of Dhul Hijja)." Then some companions of the Prophet (PBUH) said, "Not even Jihad?" He replied, "Not even Jihad, except that of a man who does it by putting himself and his property in danger (for Allah's sake) and does not return with any of those things." ))

[ Al-Bukhari by Ibn Umar ]

This man  is killed for the Sake of Allah. 
Hence, there are three Ayat in the Quran about the virtues of the ten days of Dhul-Hijjah, many As7adeth in the Noble Sunnah, and many scholars' quotes in interpreting the As7adeth, which shows clearly that these ten days are the best  days in Muslim's worldly life.

The preferable deeds to be offered in these days:

1- Offering Hajj and Umrah:

  What are the preferable deeds to be offered during these ten days? Before we answer this question, let me tell you that there are times which are peculiar in Muslim's life, such as Friday on which there is an hour when  your Du'a (supplication) to Allah is  responded. Also, Ramadan is a special month, Hajj days have certain rituals and the  time of Sahar (before Fajr) has its own peculiarity (it is included in the last third of the night.)As if Allah the Almighty meant for these days to be special occasions for the Muslim (so that he might be changed to a better Muslim):<p class="s7adeth">((Abu Sa'id and Abu Huraira reported Allah's Messenger (PBUH) as saying: Allah waits till when one-third of the first part of the night is over; He descends to the lowest heaven and says: It there any supplicator of forgiveness? Is there any penitant? Is there any petitioner (for mercy and favour)? Is there any solicitor? -till it is daybreak.))

[ Muslim by Abi Hurairah ]

The time of Sahar has its own spirituality.

(( Narrated Abu Huraira: Allah's Messenger (PBUH) said, "If the people knew the reward of 'Isha' and Fajr (morning) prayers in congregation, they would come to offer them even if they had to crawl." ))

[ Agreed upon by Abi Hurairah ]

As I have just said, the time of Sahar, Friday, the ten days of Dhul-Hijjah and the month of Ramadan have certain spiritual peculiarities. These peculiarities are related to time, and there are certain spiritual peculiarities which have to do with the space, such  as the Masjid which is a special  place, and the house of Allah (Ka'bah in Makkah) is a special place as well.
Scholars said, "Muslim should increase his good deeds and acts of worship on these occasions." The righteous ancestors used to do so on these occasions as scholars said, "The righteous ancestors used to ennoble three tens: The last ten days of Ramadan, the first ten days of Dhul-Hijjah and the first ten days of Muharram." The greatest act of worship during the ten days of Dhul-Hijjah is performing Hajj and Umrah.

﴾ And Hajj (pilgrimage to Makkah) to the House (Ka'bah) is a duty that mankind owes to Allah, those who can afford the expenses (for one's conveyance, provision and residence). ﴿

[ Aal-'Imran, 97 ]

In Hajj, the Creator of the universe invites  you to visit Him, and when the Greatest invites you, how do you think He will honor you? If a Muslim enters a Masjid, he will be honored according to the following Hadith:

(( Whoever performs ablution well in his home and thereafter comes to the mosque, then he is the guest of Allah and it is a duty upon the host to honor his guest. ))

What about entering the House of Allah in Makkah or Al-Masjid An-Nabawi (the Prophetic Masjid)? Hence, the best thing the Muslim does is to perform Hajj and Umrah during the first ten days of Dhul-Hijjah.

The rulings of Hajj:

  It is convenient here to talk about the rules of Hajj. First of all Hajj is performed only by the one who can afford it. What bewilders me is that lots of people might borrow money to perform Hajj. Are they creating a new religion other than Allah's religion? If Allah says that only the one who can afford Hajj shall perform it, so is it rational to borrow money to perform Hajj?
This morning a brother said to me,  "Such and such person borrowed 100.000, and the one who lent him the money is in dire need for them, yet that person is intending to borrow another sum of money money to perform Hajj this year." I said (given Allah knows that which in hearts), "This person might be  seeking reputation in performing Hajj, so he is not  performing it as an act of worship".
If you want to worship Allah, you should do that according to His Method, and His Method entails favoring Dar' Al-Mafasid (closing off the means that can lead to evil) over Jalb Al Manafe' (achieving good). Accordingly, this person must pay his debt before bragging about performing his 15th Hajj.

(( Abu Hurairah (may Allah be pleased with him) reported: The Messenger of Allah (PBUH) said, "(The performance of) 'Umrah is an expiation for the sins committed between it and the previous 'Umrah; and the reward of Hajj Mabrur (i.e., one accepted) is nothing but Jannah." ))

[ Agreed upon by Abi Hurairah ]

(( Narrated Abu Hurairah: The Prophet (PBUH) said, "Whoever performs Hajj for Allah's pleasure and does not have sexual relations with his wife, and does not do evil or sins then he will return (after Hajj free from all sins) as if he were born anew." ))

[ Agreed upon by Abi Hurairah]
If the ruler prevents you from Hajj, you should obey him. Every nation has  rulers and laws, so in case the ruler does not allow you to perform Hajj, do not try to bribe him to be able to go. How can you initiate performing the greatest act of worship with a sin? Is this logical? Is it reasonable to initiate this great act of worship with a false statement?
I would like to talk about Al-Hajj Al-Mabroor. Al Hajj Al Mabroor is the Hajj which is in performed according to  the Prophetic guidance. A brother told me once, "I have an outstanding clever way to perform Hajj in almost no time." I said, "Please enlighten me." He continued, "We offer Asr Salah in Jiddah" to which I asked, "When can we do that?" He replied, "On Arafah Day." I said, "Ok, carry on." He said, "On that day the road to Makkaha is almost empty, so we enter Al-Masjid Al-Haram (Ka'bah Haram), and we offer Tawaf (circumambulation). At this time you can barely find ten people other than you offering Tawaf, so you can do Tawaff in less than 15 minutes and you can circumambulate very close to Ka'bah. After that,  you offer the rite of Sa'i (rushing between the hills of Safa and Marwah seven times) which will take no more than half an hour. Afterwards, we reach Arafat by  the last car, given the road is empty at that time of the day. We stay there only 10 minutes till the sun sets, and then we head to the rite of Rajm AlJimar of Jamret Al-Aqabah (the act of pelting the Jimar at Mina with pebbles.) as the road is also empty. Then, we offer the rite of Tawaf Al-Ifadah (re-visiting the Masjid Al-Haram and circumambulating Ka'bah) around 8:00 or 9:00 PM where there is no one in Al-Haram. Then we can ask someone else to perform the rite of Rami on our behalf the rest of the days (the second, the third and the fourth days)." I said to him, "Wow, this kind of Hajj is like being invited to a very exquisite banquet of all sorts of tasty food, but what we do is just checking in, proving that our presence at the banquet, and then leaving  without eating anything." 
Keep in mind that the best act of worship during these ten days is performing Hajj and Umrah. AlHajj Al-Mabroor is referred to in the following Hadith: 

(( Narrated Abu Hurairah: The Prophet (PBUH) said, "Whoever performs Hajj for Allah's pleasure and does not have sexual relations with his wife, and does not do evil or sins then he will return (after Hajj free from all sins) as if he were born anew." ))

[ Agreed upon by Abu Hurairah ]

Al-Hajj Al-Mabroor is the Hajj which is not tainted by sins, hypocrisy, seeking reputation, sexual relation with one's wife or evil doings, so it  is the one which is accompanied with good deeds.

2- Observing Sawm:

  Among the good deeds performed on the ten days of Dhul-Hijjah is to observe Sawm. If man's health allows him to observe Sawm, if his career is not troublesome, if he is retired or does not get tired of fasting, performing Sawm on those ten days is the best act of worship, provided the one who performs Sawm should not criticize or blame the one who does not.
The companions were the best example in their politeness, while nowadays people make fuss about their voluntary Sawm. For instance, the one who performs voluntary Sawm tells everyone that he is fasting, and he even wonders if those around him observe Sawm, so if he is fasting on the Day of Ashoorah, he keeps asking sh3er if they observe Sawm or not saying that it is a blessed day. Well, if you perform voluntary Sawm, keep quiet and do not embarrass sh3er.
The companions were the top in their politeness, so  in some expeditions, some of them performed Sawm, while sh3er did not (some of them used Al-Rukhsah [An exception to a general law, granted to preserve life or remove hardship] and broke their fasting while traveling unlike sh3er who used the Azimah [determination, as they kept fasting though they are traveling]). Thus, those who fasted did not criticize those who broke their fasting, and the latter did not criticize those who kept fasting. This behavior reflects their politeness and exalted traits.
Some people are strong enough, and the retired who do not have to go to work, fast the whole ten days, but sh3er might have a burdensome work, or if they perform Sawm the entire ten days they will get tired and that will affect their career, so they fast on Arafah Day only. Hence, whoever has the ability to perform Sawm on the entire ten days, let him offer Sawm, and whoever cannot, let him not perform Sawm, provided the former should not criticize the latter and vice versa.

(( It was narrated that Anas bin Malik said: "We were with the Messenger of Allah on a journey, and some of us were fasting and some of us were not. We made a stop on a hot day and looked for shade. Those who were fasting fell to the ground, but those who were not fasting got up and watered the animals. The Messenger of Allah said: 'Those who were not fasting today have taken the reward." ))

Muslim by Anas
He referred to those who did not observe Sawm. One might offer about 50 good deeds, and he needs a physical strength to perform them, so if breaking his voluntary fasting is more appropriate for him, let him break it and accomplish those good deeds.  If fasting  threatens man's health due to the sever conditions, man can follow the steps of the Prophet as it is mentioned in the following Hadith:

(( Jabir (RAA) narrated, 'The Messenger of Allah (PBUH) left for Makkah during the year of the conquest (of Makkah) in Ramadan and he and the people with him fasted until he reached the valley of Kura Al-Ghamim. He then called for a cup of water, which he elevated so that the people could see it, and then he drank. After-wards, he was told that some people had continued to fast, and he then said, "Those are the disobedient ones! Those are the disobedient ones!" ))

[ Al-Muwata' by Jabir ]

This is but claiming to be more religious than the Prophet PBUH himself.

(( Those are the disobedient ones! Those are the disobedient ones! ))

[ Al Muwata' by Jabir ]

They are not more devoted than the Prophet PBUH, and they are not keener than him on their connection with Allah.
Let me repeat again, the preferable act of worship in these ten days is to observe Sawm, provided you have the ability to do it, and avoid  bragging about it. Hence, observe Sawm and keep quiet.
A brother I know said to me once, "I raised my kids to thank Allah for whatever they eat, so if they eat a tasty food they thank Allah, if they eat olives they thank Allah and if they eat poor food they also thank Allah. Once, my wife cooked something that they did not like, so they mumbles, but I said to them, 'Eat and keep quiet.'" When you observe Sawm do that and keep quiet, and do not claim to be more pious than those who did not observe Sawm, and do not embarrass them by asking or commenting. Allah says in a Qudsi Hadith:

(( Narrated Abu Hurairah: The Prophet (PBUH) said, "(Allah said), 'Every good deed of Adam's son is for him except fasting; it is for Me. and I shall reward (the fasting person) for it.' ))

[ Agreed upon by Abi Huraira ]

As I said earlier,  the greatest act of worship in these ten days is to perform Hajj and Umrah regarding  those who are honored of traveling to Hajj, but as for those who do not travel to Hajj, Sawm (for the one who is able to perform it) is the best act of worship during these ten days as a voluntary act of worship, but with regard to performing Sawm on the Day  of Arafah, it is Sunnah Mu'akkadah (confirmed Sunnah). 

(( Abu Qatadah narrated that: the Prophet said: "Fast the Day of Arafah, for indeed I anticipate that Allah will forgive (the sins) of the year after it, and the year before it." ))

[ Muslim by Abi Qatadah ]

According to Imam An-Nawawi, it is Mustahab (preferable) to offer Sawm on those ten days.

3- Performing Salah:

  The third best act of worship during these ten days is Salah which is the greatest and the most favored act of worship at all:

(( Abu Hurairah (may Allah be pleased with him) reported: Messenger of Allah (PBUH) said, "Allah, the Exalted, has said: 'I will declare war against him who treats with hostility a pious worshipper of Mine. And the most beloved thing with which My slave comes nearer to Me, is what I have enjoined upon him; and My slave keeps on coming closer to Me through performing Nawafil (voluntary prayers or doing extra deeds besides what is obligatory) until I love him, (so much so that) I become his hearing with which he hears, and his sight with which he sees, and his hand with which he strikes, and his leg with which he walks; and if he asks Me something, I will surely give him, and if he seeks My Protection (refuge), I will surely protect him." ))

[ Al-Bukhari by Abi Hurairah ]

4- At Takbir, At Tahlil, At Tahmeed and Al Dhikr:

  Takbir (Uttering that Allah is The Greatest), Tahlil (Uttering La Ilaha Illa Allah), Tahmeed (Praising Allah) and Dhikr (Remembering Allah) are also among the best acts of worship to offer during these ten days.
Remembering Allah includes many deeds, so it is not restricted to attending Dhikr assemblies as some people assume, but rather  you can offer Dhikr if you talk to  people about Allah, teach them His Beautiful Names and Exalted Attributes, tell them about the perfection of the Prophets, peace be upon them, pass what you know about the interpretation of the Quran to sh3er, teach them what you know about Sunnah or tell them stories of the companions. All these deeds are Da'wah activities, as Dhikr is of three kinds, Dhikr that aims to teach people, Dhikr that includes Islam rulings and Dhikr as an act of worship. Hence, every activity or deed that draws you close to Allah is considered Dhikr, and it is preferable for the Muslim to offer Dhikr during these ten days. 

(( Narrated Ibn Umar, may Allah be pleased with them both, said that the Prophet PBUH said: "There are no days greater and more beloved to Allah then these ten days of Dhul-Hijjah, so increase in them your declaration of the oneness of Allah (Tahlil), your exaltation of Him (Takbir), and your praise of Him (Tahmeed)." ))

[ Ahmad by Ibn Umar ]

Unfortunately, people offer Tahlil (Uttering La Ilaha Illah Allah) only when they are angry with someone, and they do Salah ala An-Nabi (saying: blessings and peace of Allah be upon the Prophet PBUH) only when they argue with one another, while they are expected to do so on regular basis, and not only in arguments and conflicts. 

(( Imam Al-Bukhari narrated: "Ibn 'Umar and Abu Hurayrah, may Allah be pleased with them both, used to go out to the markets in the ten days saying the takbir causing the people to follow them in this action, as would the people in the markets until the whole of Mina was locked in glorifying Allah. ))

[ Al-Bukhari by Ibn Umar ]

  Ibn Umar used to say the Takbir during these ten days in Mina, after offering Salah, on his bed and in his assembly, and when he walks. Hence, it is preferable to offer Takbir, Tahlil and Dhikr during these days. The bitter truth is that Muslims nowadays utter these words meaninglessly, for the one who obeys a person and disobeys Allah, has never uttered Takbir not even once though he might utter it thousand times with his tongue, since he believes that earning more money by deceiving and cheating Muslims is more important to him than obeying Allah. Also, whoever obeys his wife and disobeys Allah to please her has never uttered Takbir not even one time though he might say it thousand times with his tongue. In fact, Allahu Akbar is the most important phrase in Islam, yet the majority of people repeat it without paying attention to its meaning, for Akbar  means that Allah is Greater than any powerful man, any mundane gains and any enemy of Islam.
The enemy frightens the Muslim when the latter's faith is weak, and so he says, "they have missiles, nuclear weapons, satellites and fighting jets, while we, Muslims, are weak. Such a person has never considered Allah Greater than that enemy, but he is frightened by the latter due to his weak faith, and he forgets about Allah the Almighty entirely.

 5- Sadaqah (Almsgiving):

  Sadaqah is amongst the preferable acts of worship that should be offered on these ten days. Allah says:

﴾ O you who believe! Spend of that with which We have provided for you, before a Day comes when there will be no bargaining, nor friendship, nor intercession. And it is the disbelievers who are the Zalimun (wrong-doers, etc.). ﴿

[ Al-Baqarah, 254 ]

The Prophet PBUH said:

(( The wealth of a man will not diminish by Sadaqah (charity). ))

[ Muslim and At-Tirmizi by Abi Hurairah ]

6- Offering all sorts of good deeds

Let me mention some of the good deeds that should be offered on these ten days. These good deeds include reciting the Quran, learning the Quran, teaching the Quran, being dutiful to parents, asking Allah for forgiveness, strengthening kin ties, greeting people, feeding the hungry, reconciling people with one another, enjoining Ma'ruf, forbidding Munkar, watching the tongue, keeping chaste, being generous to neighbors, being hospital to guests, spending in the Cause of Allah, removing from the road what might harm people, spending on the wife and children, sponsoring orphans, visiting the sick, meeting Muslims' needs, Salah ala An-Nabi, avoiding hurting Muslims, being gentle towards citizens, visiting parents' friends, making Du'a for brother in faith, rendering trusts, fulfilling promises, being dutiful to the aunt and uncle, helping the one in hardship, lowering the gaze from looking at forbidden things, offering Wudu abundantly, offering Du'a between Azan and Iqamah, reading Surat Al--Kahf on Friday, going to the Masjid, being keen on offering Salah in congregation, being keen on offering regular Sunan, being keen on offering Eid Salah, remembering Allah following every Salah, accepting only Halal money and bringing joy to Muslims.

Unfortunately, Muslims artfully try nowadays to hurt one another, for some people enjoy hurting sh3er, and  they rejoice frightening them. On the other hand, the foremost concern of the true Muslim is to bring joy to Muslims' life, to sympathize with the weak and the wretched, to do sh3er favor, to lead sh3er to goodness, to be keen on having a pure heart, to avoid hostility, to teach boys and girls and to cooperate with other Muslims in the cause of Birr (good deeds) and Taqwah (righteousness). This is a list of the good deeds that are recommended to be offered on these ten days.
Dear brother, these ten days are the best days in the worldly life, so if the Hujjaj are right now circumambulating Ka'bah and visiting Al-Masjid An-Nabawi, the least we can do since we are not Hujjaj, is to observe Sawm, to offer Salah, to give Sadaqah and to offer good deeds on these days, so that may Allah the Almighty endue us with One of His Divine Whiffs.