Sahih Muslim , Book 4, Hadith 1036 (USC-MSA) ⓘ
'A'isha reported: The Apostle of Allah said his whole prayer (Tahajjud prayer) during the night while I lay between him and the Qibla. When he intended to say Witr (prayer) he awakened me and I too said witr (prayer).
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا وَكِيعٌ، عَنْ هِشَامٍ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، قَالَتْ كَانَ النَّبِيُّ صلى الله عليه وسلم يُصَلِّي صَلاَتَهُ مِنَ اللَّيْلِ كُلَّهَا وَأَنَا مُعْتَرِضَةٌ بَيْنَهُ وَبَيْنَ الْقِبْلَةِ فَإِذَا أَرَادَ أَنْ يُوتِرَ أَيْقَظَنِي فَأَوْتَرْتُ .
also referenced under: Book 4, Hadith 303 (In-Book) & Hadith 512 (Reference)