It was narrated that Ubayy bin Ka'b said:"In the first rak'ah of witr, the Messenger of Allah (ﷺ) used to 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

English translation · Sunan an-Nasa'i