(The Messenger of Allah (PBUH) used to pray in the night and when he observed Witr, he said to me: O 'A'ishah, get up and observe Witr.)

[Bukhari and Muslim]

The members of every family at the Prophetic time used to wake one another up in order to offer the acts of worship.

(It was narrated that Abu Hurairah said: "The Messenger of Allah (PBUH) said: 'May Allah have mercy on a man who gets up at night and prays, and wakes his wife, and she prays; and if she refuses he sprinkles water in her face. And May Allah have mercy on a woman who gets up at night and prays, and wakes her husband and he prays; and if he refuses, she sprinkles water in his face.'")

[Abu Dawod, An-Nasa'i and Ahmad]