Sunan an-Nasa'i 1756

Abu Salamah bin Abdur-Rahman narrated that :He asked Aishah about the prayer of the Messenger of Allah (ﷺ) at night. She said: "He used to pray thirteen rak'ahs: nine rak'ahs standing, one of which was witr, and two rak'ahs sitting. When he wanted to bow he would stand up, and bow and prostrate, and he did that after witr. Then when he heard the call for Subh, he stood up and prayed two brief rak'ahs