سُنَنُ النَّسَائِيِّ
Sunan an-Nasa’i 1696
The Book of Qiyam Al-Lail (The Night Prayer) and Voluntary Prayers During the Day
How to pray witr with one (rak'ah)
أَخْبَرَنَا إِسْحَاقُ بْنُ مَنْصُورٍ، قَالَ أَنْبَأَنَا عَبْدُ الرَّحْمَنِ، قَالَ حَدَّثَنَا مَالِكٌ، عَنِ الزُّهْرِيِّ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ يُصَلِّي مِنَ اللَّيْلِ إِحْدَى عَشْرَةَ رَكْعَةً يُوتِرُ مِنْهَا بِوَاحِدَةٍ ثُمَّ يَضْطَجِعُ عَلَى شِقِّهِ الأَيْمَنِ .
It was narrated from 'Aishah that: The Prophet (ﷺ) used to pray eleven rak'ahs at night, ending them with one rak'ah of witr, then he would lie down on his right side.
Sunan an-Nasa'i, 1696Sahih (Darussalam)