Musnad Abu Ya'la al-Mawsili 116:31

Ahmad narrated to us, Abu Dawud narrated to us, he said: Shu'bah informed us, from Qatadah, from Anas, who said: I prayed behind the Messenger of Allah (may Allah bless him and grant him peace), and behind Abu Bakr, and behind Umar, and behind Uthman. They did not begin the recitation with "In the name of Allah, the Most Gracious, the Most Merciful." Shu'bah said: I said to Qatadah, "Did you hear it from Anas?" He said, "Yes, I asked Anas about it."