Hazrat Anas (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings be upon him) said: If a person forgets to perform a prayer or sleeps without having performed it, its expiation is that he should offer it as soon as he remembers.

Hazrat Abdullah bin Masood (may Allah be pleased with him) narrates that when we were returning with the Messenger of Allah (peace and blessings be upon him) from Hudaybiyyah, we camped on a sandy land. The Noble Prophet (peace and blessings be upon him) said, "Who will wake us up?" Hazrat Bilal said, "I will wake you." The Prophet (peace and blessings be upon him) said, "Then we will sleep." So everyone slept and remained asleep until the sun had risen. Then some people woke up, among them so-and-so and Hazrat Umar as well. We said, "Let us go and speak." Then the Noble Prophet (peace and blessings be upon him) also woke up and said, "Continue as you were doing." So we did the same, and the Messenger of Allah (peace and blessings be upon him) said, "Whoever sleeps through the time of prayer or forgets it, this is the ruling for him."

Hazrat Abu Huraira says that in the last part of one night, we camped with the Prophet Muhammad (peace and blessings be upon him). In the morning, none of us woke up until the sun had risen. The Prophet Muhammad (peace and blessings be upon him) said to us that everyone should take hold of his mount and leave this place. Then he asked for water, performed ablution, and made two prostrations. Then the call to prayer was given for the prayer, and he led us in prayer.

Hazrat Abu Juhaifa narrates that in that journey during which everyone had slept and the sun had risen, the Holy Prophet (peace and blessings be upon him) said, "You were in a state of death; Allah, the Exalted, returned your souls to you. Whoever sleeps at the time of prayer or forgets to offer the prayer, then whenever he wakes up or remembers, he should offer it at that time."

Hazrat Ali (may Allah be pleased with him) says that when a person forgets to offer a prayer or falls asleep, then whenever he remembers or wakes up, he should offer it at that time.

Hasan narrates that there was a disagreement between Hazrat Samurah bin Jundub and Hazrat Imran bin Husain regarding the person who forgets to perform a prayer. Hazrat Imran bin Husain said that he should perform it whenever he remembers, and Hazrat Samurah said that he should perform it whenever he remembers or on the next day at its time.

Hazrat Ibn Abbas (may Allah be pleased with them both) said: He should recite it whenever he remembers.

Hazrat Saad says that when he remembers it, he should offer it at that time, and on the next day, he should offer a similar prayer at its (prescribed) time.

Ibrahim says that if a person forgets to pray or sleeps through the time of prayer, then whenever he remembers, whether it is at sunrise or sunset, he should pray at that time. Then he recited this verse { أَقِمِ الصَّلاَۃ لِذِکْرِی } and then said that whenever you remember, pray at that time, no matter what time it is.

Hazrat Abu Dharr and Hazrat Abdur Rahman bin Awf, regarding the person who forgets to perform the prayer, say that when he remembers, he should perform it at that time.