It wasnarrated from Ibn 'Abbas that the Messenger of Allah (ﷺ)used toperform Witr and recite:
"Glorify the Name of your Lord theMostHigh," [Al-A'la (87)] "Say: O you disbelievers!" [Al-Kafirun(109)] and 'Say: Allah is One.". [Al-Ikhlas (112)]Another chain with similar wording. (IT)
English reference (IT): Vol. 1, Book 5, Hadith 1172 (IT)
Arabic reference (IT): Book 5, Hadith 1227 (IT)