Musnad Ahmad 32:714

'Abd al-Razzaq narrated to us, he said: Abu Ja'far—meaning al-Razi—narrated to us, from al-Rabi' ibn Anas, from Anas ibn Malik, who said: "The Messenger of Allah, peace and blessings of Allah be upon him, did not cease to perform Qunut in the Fajr prayer until he departed from the world."