Qatada narrated on the authority of Anas b. Malik that the Messenger of Allah (ﷺ) said: He who forgets the prayer, or he slept (and it was omitted), its expiation is (only) that he should observe it when he remembers it.

Qatada reported it on the authority of Anas b. Malik that the Messenger of Allah (ﷺ) said: When any one of you omits the prayer due to sleep or he forgets it, he should observe it when he remembers it, for Allah has said:" Observe prayer for remembrance of Me."