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 Book 20, Hadith 99
← Previous Hadith He heard the Messenger of Allah (ﷺ) say: "Prayer at night is two rak'ahs by two rak'ahs, then when you fear tat dawn will break, pray witr with one rak'ah."

Sunan an-Nasa'i Book 20, Hadith 98 Next Hadith → He asked Aishah, the Mother of the Believers, about how the Messenger of Allah (ﷺ) used to pray in Ramadan. She said: "The Messenger of Allah (ﷺ) did not pray more than eleven rak'ahs during Ramadan or at any other time. He would pray four, and do not ask how beautiful or how long they were. Then he would pray four, and do not ask how beautiful or how long they were. Then he would pray three." Aishah said: "I said: 'O Messenger of Allah, do you sleep before you pray witr?' He said: 'O Aishah, my eyes sleep but my heart does not.'"

Sunan an-Nasa'i Book 20, Hadith 100