It wasnarrated that Ubayy bin Ka'b said:
"The Messenger of Allah(ﷺ)used to perform Witr and recite: 'Glorify the Name of your LordtheMost High.', [Al-A'la (87)] 'Say: O you disbelievers!"[Al-Kafirun(109)] and 'Say: Allah is One.". [Al-Ikhlas (112)] (IT)
English reference (IT): Vol. 1, Book 5, Hadith 1171 (IT)
Arabic reference (IT): Book 5, Hadith 1226 (IT)