Musnad Abu Ya'la al-Mawsili 114:11

Sufyan ibn Waki' narrated to us, Abd al-Wahhab narrated to us, from Khalid, from Muhammad, who said: I asked Anas ibn Malik, "Did Umar perform Qunut?" He said, "Indeed, one who is better than Umar performed Qunut; the Prophet, may Allah bless him and grant him peace, performed Qunut."