كتاب المواقيت
6  
The Book of the Times (of Prayer)
(53)
Chapter: Concerning One Who Sleeps And Misses A Prayer
(53)
باب فِيمَنْ نَامَ عَنْ صَلاَةٍ
Sunan an-Nasa'i 614
It was narrated that Anas said:
"The Messenger of Allah (ﷺ) was asked about a man who slept and missed the prayer, or forgot it. He said: 'The expiation for that is to pray it when he remembers it.'"
أَخْبَرَنَا حُمَيْدُ بْنُ مَسْعَدَةَ، عَنْ يَزِيدَ، قَالَ حَدَّثَنَا حَجَّاجٌ الأَحْوَلُ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ سُئِلَ رَسُولُ اللَّهِ صلى الله عليه وسلم عَنِ الرَّجُلِ يَرْقُدُ عَنِ الصَّلاَةِ أَوْ يَغْفُلُ عَنْهَا قَالَ ‏ "‏ كَفَّارَتُهَا أَنْ يُصَلِّيَهَا إِذَا ذَكَرَهَا ‏"‏ ‏.‏
Grade: Sahih (Darussalam)
Reference : Sunan an-Nasa'i 614
In-book reference : Book 6, Hadith 121
English translation : Vol. 1, Book 6, Hadith 615