Musannaf Ibn Abi Shayba 3:4534

Yazid ibn Harun narrated to us, from Hisham al-Dastawa'i, from Hammad, from Ibrahim, from Alqama: That Ibn Mas'ud and the companions of the Prophet, may Allah bless him and grant him peace, used to perform the Qunut in the Witr prayer before the bowing (ruku').