Sunan At-Tirmidhi

Ali narrated:""Allah's Messenger would perform Al-Witr with three, reciting nine Surah from the Mufassal in them, reciting three Surah in each Rak'ah with Say: ""Allah is One."" At the end of them.""Muhammad bin Sirin said: ""They would perform Al-Witr with five, with three, and with one Rak'ah, and they considered all of that to be good