كتاب الْمَسَاجِدِ وَمَوَاضِعِ الصَّلاَةِ
5
The Book of Mosques and Places of Prayer
(55)
Chapter: Making up a missed prayer. And it is recommended to hasten to make it up
(55)
باب قَضَاءِ الصَّلاَةِ الْفَائِتَةِ وَاسْتِحْبَابِ تَعْجِيلِ قَضَائِهَا ‏‏

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.
وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا عَبْدُ الأَعْلَى، حَدَّثَنَا سَعِيدٌ، عَنْ قَتَادَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ قَالَ نَبِيُّ اللَّهِ صلى الله عليه وسلم ‏ "‏ مَنْ نَسِيَ صَلاَةً أَوْ نَامَ عَنْهَا فَكَفَّارَتُهَا أَنْ يُصَلِّيَهَا إِذَا ذَكَرَهَا ‏"‏ ‏.‏
Reference : Sahih Muslim 684 c
In-book reference : Book 5, Hadith 404
USC-MSA web (English) reference : Book 4, Hadith 1456
  (deprecated numbering scheme)