"Messenger of Allah (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." (Using translation from Tirmidhī 440)
أَنَّ رَسُولَ اللهِ ﷺ كَانَ «يُصَلِّي بِاللَّيْلِ إِحْدَى عَشْرَةَ رَكْعَةً يُوتِرُ مِنْهَا بِوَاحِدَةٍ فَإِذَا فَرَغَ مِنْهَا اضْطَجَعَ عَلَى شِقِّهِ الْأَيْمَنَ»