Muwatta Imam Malik Book of Tahajjud, Hadith 8

Yahya related to me from Malik from Ibn Shihab from Urwa ibn az- Zubayr from A'isha, the wife of the Prophet ﷺ that the Messenger of Allah ﷺ used to pray eleven rakas in the night, making them odd by a single one, and when he had finished he lay down on his right side.

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ عُرْوَةَ بْنِ الزُّبَيْرِ، عَنْ عَائِشَةَ، زَوْجِ النَّبِيِّ ﷺ . أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يُصَلِّي مِنَ اللَّيْلِ إِحْدَى عَشْرَةَ رَكْعَةً يُوتِرُ مِنْهَا بِوَاحِدَةٍ فَإِذَا فَرَغَ اضْطَجَعَ عَلَى شِقِّهِ الأَيْمَنِ .