Praise be to Allah, the Lord of the Worlds, and I testify that there is no Deity worthy of worship but Allah Alone, the Guardian of the pious, and I testify that our Master Muhammad is his slave and Messenger, who is on an exalted standard of character.
What is forbidden due to marriage is forbidden due to fosterage:
In His Divine Book, the Noble Quran, Allah the Almighty says:
﴾ Forbidden to you (for marriage) are: your mothers, your daughters, your sisters, your father's sisters, your mother's sisters, your brother's daughters, your sister's daughters, your foster mother who gave you suck, your foster milk suckling sisters, your wives' mothers, your step daughters under your guardianship, born of your wives to whom you have gone in - but there is no sin on you if you have not gone in them (to marry their daughters), - the wives of your sons who (spring) from your own loins, and two sisters in wedlock at the same time, except for what has already passed; verily, Allah is Oft-Forgiving, Most Merciful. ﴿
Pay attention to the following Hadith, please:
(( Yahya related to me from Malik from Hisham ibn Urwa from his father that A'ishah, umm al-muminin (the Mother of the Believers), may Allah be pleased with herm said, "My paternal uncle by suckling came to me and I refused to give him permission to enter until I had asked the Messenger of Allah, may Allah bless him and grant him peace, about it. The Messenger of Allah, may Allah bless him and grant him peace, came and I asked him about it. He said, 'He is your paternal uncle, so give him permission.' So I said, 'Messenger of Allah! The woman nursed me not the man.' He said, 'He is your paternal uncle, so let him enter.' " A'ishah said, "That was after the veil had been imposed on us." A'ishah added, "What is haram (forbidden) by birth is made haram by suckling." ))
[ Al-Bukhari, Muslim, At-Tirmithi, Ibn Majah and Malik
]
The above-mentioned Ayah and Prophetic Hadith show clearly that fosterage makes a foster infant the real son of the foster mother and the brother or sister of those who share fosterage with him/her from the same foster mother. Most up-to-date studies in genetics confirm that kinship due to fosterage is not only real but also transferred to forthcoming generations.
Modern genetics also confirm that fosterage transfers some genes from the foster mother to the infant. Such foster kinship, which not only Allah the Almighty (in the Noble Quran) but also Allah's Messenger PBUH consider as real as that of marriage is scientifically explained by the fact that genes are transferred through the foster mother's milk to the infant. These genes enter into and mingle with the infant's cells, forming a new series of genes that can be transferred from the infant to following generations.
What scientists say about fosterage:
Geneticists also say that milk contains more than one kind of cells and that the infant's genetic system accepts alien genes, as it is still immature, and adds them up to its original system. Therefore, when a woman gives suck to an infant, the genes in her milk enter into the infant's cells and settle therein, reaching its genetic system and constituting a part thereof. These facts explain why Allah's Messenger PBUH said the following:
(( What is haram (forbidden) by birth is made haram by suckling ))
Allah's Messenger PBUH never speaks out of his own desire or imagination, but it is an inspiration inspired to Him. Hence, all that is mentioned in the Noble Quran, and the sound Prophetic Sunnah is scientifically firmly established. Nowadays, it has become well-known to modern geneticists that milk is made up of cells that enter into the infant's tissues and mingle with its original genes and that the infant's genetic system accepts the new alien genes and allows them to become a part thereof. I repeat the words of the Prophet PBUH:
(( What is haram (forbidden) by birth is made haram by suckling ))
