It was narrated from Ubayy bin Ka'b that:
The Messenger of Allah (ﷺ) used to pray witr with three rak'ahs. In the first he would recite: Glorify the Name of Your Lord, the Most High in the second: Say: O you disbelievers! , and in the third: Say: He is Allah, (the) One . And he would say the Qunut before bowing, and when he finished he would say: Subhanal-Malikil-Quddus (Glory be to the Sovereign, the Most Holy) three times, elongating the words the last time.