Sunan Abi Dawud 8:9

Narrated Aisha, Ummul Mu'minin:

AbdulAziz ibn Jurayj said: I asked Aisha, mother of the believers: With which (surah) the Messenger of Allah (ﷺ) used to observe witr? (She reported same as in the Hadith of Ubayy ibn Ka'b, No. 1418) This version adds: In the third rak'ah he would recite: "Say, He is Allah, the One" (Surah 112), and "Say, I seek refuge in the Lord of daybreak" (Surah 113), and "Say, I seek refuge in the Lord of mankind" (Surah 114).