Jami` at-Tirmidhi, Volume 1, Book 2, Hadith 440 (DarusSalam) ⓘ
Aishah narrated: "Allah's Messenger (S) would pray eleven Rak'ah at night, making them off with one. When he finished them he would lay down on his right side."
حَدَّثَنَا إِسْحَاقُ بْنُ مُوسَى الأَنْصَارِيُّ، حَدَّثَنَا مَعْنُ بْنُ عِيسَى، حَدَّثَنَا مَالِكٌ، عَنِ ابْنِ شِهَابٍ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يُصَلِّي مِنَ اللَّيْلِ إِحْدَى عَشْرَةَ رَكْعَةً يُوتِرُ مِنْهَا بِوَاحِدَةٍ فَإِذَا فَرَغَ مِنْهَا اضْطَجَعَ عَلَى شِقِّهِ الأَيْمَنِ .
also referenced under: Hadith 440 (Reference) & Book 2, Hadith 293 (In-Book)