Musannaf Ibn Abi Shayba 3:4535

Yazid ibn Harun narrated to us, he said: Aban ibn Abi Ayyash informed us, from Ibrahim, from Alqama, from Abdullah, that the Prophet (peace and blessings of Allah be upon him) used to perform Qunut in the Witr prayer before the bowing (Ruku). He said: Then my mother, Umm Abd, sent me, and she spent the night with his wives, and she informed me that he performed Qunut in the Witr prayer before the bowing.