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
← Previous Hadith A man asked the Messenger of Allah (ﷺ) about prayer at night and the Messenger of Allah (ﷺ) said: "Prayer at night is two by two, then if one of you fears that dawn will break, pray one rak'ah to make the total number that he prayed odd."

Sunan an-Nasa'i Book 20, Hadith 97 Next Hadith → 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