It is narrated from Hazrat Anas that the Holy Prophet (peace and blessings be upon him) said: Whoever forgets to perform a prayer or sleeps through its time, its expiation is that when he remembers the prayer, he should perform it.

Hazrat Abdullah bin Mas'ud (may Allah be pleased with him) narrates that we were returning from Hudaybiyyah with the Noble Prophet (peace and blessings be upon him). The companions state that they stopped at a sand dune. Ibn Mas'ud says, the Messenger of Allah (peace and blessings be upon him) said: "Who will guard us?" The narrator says that Hazrat Bilal said: "I will!" So the Noble Prophet (peace and blessings be upon him) said: "Then we will sleep." The narrator says that everyone slept until the sun rose. The narrator says: a few people woke up, among them so-and-so and so-and-so, and among them was Umar bin Khattab as well. They say that then we said: "Talk amongst yourselves." The narrator says that then the Noble Prophet (peace and blessings be upon him) also woke up and he said: "Do as you were doing." The narrator says that then we did (i.e., we prayed). The narrator says that the Prophet (peace and blessings be upon him) said: "Whoever forgets a prayer or sleeps through it, let him do as you have done."

Hazrat Aun bin Abi Hujayfah narrates from his father that the Messenger of Allah, peace and blessings be upon him, said to those people who had slept with him until sunrise: "You were dead, then Allah returned your souls to you. So, whoever sleeps through the time of prayer or forgets the prayer, then whenever he remembers it or wakes up from sleep, he should perform the prayer."

It is narrated from Hazrat Abu Hurairah that one night we camped with the Prophet (peace and blessings be upon him), and we woke up when the rays of the sun had appeared. The Noble Prophet (peace and blessings be upon him) said: Each of you should take hold of the end of his saddle and move away from this place. Then the Prophet (peace and blessings be upon him) asked for water, performed ablution, and offered two prostrations. Then the call for prayer was given, and the Prophet (peace and blessings be upon him) led the prayer. And it was mentioned that (Imam) Abu Hanifa's opinion is: When a person wakes up at the time of sunrise or sunset and performs the prayer (at that time), it will not suffice for him.