Musnad Abu Ya'la al-Mawsili 115:190

Muhammad narrated to us, Abd al-Razzaq narrated to us, Ma'mar informed us, from Qatadah, Humayd al-Tawil, and Aban, all of them from Anas, who said: I heard the Messenger of Allah (may Allah bless him and grant him peace), Abu Bakr, Umar, and Uthman beginning the recitation with "Al-hamdu lillahi rabbil-'alamin" (All praise is due to Allah, Lord of the worlds).