Language:
كتاب الصلاة
8  
Prayers (Salat)
(103)
Chapter: To offer As-Salat (the prayer) behind a sleeping person
(103)
باب الصَّلاَةِ خَلْفَ النَّائِمِ
Sahih al-Bukhari 512

Narrated `Aisha:

The Prophet (ﷺ) used to pray while I was sleeping across in his bed in front of him. Whenever he wanted to pray witr, he would wake me up and I would pray witr.

حَدَّثَنَا مُسَدَّدٌ، قَالَ حَدَّثَنَا يَحْيَى، قَالَ حَدَّثَنَا هِشَامٌ، قَالَ حَدَّثَنِي أَبِي، عَنْ عَائِشَةَ، قَالَتْ كَانَ النَّبِيُّ صلى الله عليه وسلم يُصَلِّي وَأَنَا رَاقِدَةٌ مُعْتَرِضَةٌ عَلَى فِرَاشِهِ، فَإِذَا أَرَادَ أَنْ يُوتِرَ أَيْقَظَنِي فَأَوْتَرْتُ‏.‏
Reference : Sahih al-Bukhari 512
In-book reference : Book 8, Hadith 159
USC-MSA web (English) reference : Vol. 1, Book 9, Hadith 491
  (deprecated numbering scheme)