A forgotten prayer

Whoever forgets or sleeps through a prayer should pray it as soon as he remembers.

Narrated by Anas ibn Malik

Whoever forgets a prayer, let him pray it when he remembers it; there is no expiation for it except that. Then he recited: "And establish the prayer for My remembrance" (Ta-Ha 20:14).

Sahih al-Bukhari 597, Sahih Muslim 684

What this hadith teaches

A missed prayer is not left; it is made up straight away. Sleeping through or forgetting is excused, but the prayer is still owed.

Reference and grade

Grade
Sahih: agreed upon by al-Bukhari and Muslim
Narrator
Anas ibn Malik

The hadith in Arabic نص الحديث

مَنْ نَسِيَ صَلاَةً فَلْيُصَلِّ إِذَا ذَكَرَهَا، لاَ كَفَّارَةَ لَهَا إِلاَّ ذَلِكَ ‏"‏‏.‏ ‏‏{‏وَأَقِمِ الصَّلاَةَ لِذِكْرِي‏}

Arabic text of Sahih al-Bukhari 597, as given on sunnah.com.