Sunan An-Nasa'i - سنن النسائي
9. The Book of the Qiblah - كتاب القبلة
10) Chapter: The concession allowing praying behind one who is sleeping
It was narrated that Aisha said:
"The Messenger of Allah(ﷺ)used to pray at night while I was lying down sleeping between him and the Qibla on his bed. When he wanted to pray witr he would wake me up and I would pray witr"
10) باب الرُّخْصَةِ فِي الصَّلاَةِ خَلْفَ النَّائِمِ
أَخْبَرَنَا عُبَيْدُ اللَّهِ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا يَحْيَى، عَنْ هِشَامٍ، قَالَ حَدَّثَنَا أَبِي، عَنْ عَائِشَةَ، قَالَتْ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُصَلِّي مِنَ اللَّيْلِ وَأَنَا رَاقِدَةٌ مُعْتَرِضَةٌ بَيْنَهُ وَبَيْنَ الْقِبْلَةِ عَلَى فِرَاشِهِ فَإِذَا أَرَادَ أَنْ يُوتِرَ أَيْقَظَنِي فَأَوْتَرْتُ .