Musannaf Ibn Abi Shayba 3:4586

Ibn Idris narrated to us, from Abu Malik, from his father, who said: I said to him, "I prayed behind the Messenger of Allah (peace and blessings of Allah be upon him), and Abu Bakr, and Umar, and Uthman; did they perform Qunut?" He said, "No, my son. It is an innovation."