Musnad Ahmad 32:2107

'Affan narrated to us, Hammad ibn Salamah narrated to us, from Qatadah, and Thabit, and Humayd, from Anas, "That the Prophet, may Allah bless him and grant him peace, and Abu Bakr, and 'Umar, and 'Uthman used to begin the recitation with {All praise is due to Allah, Lord of the worlds} [Al-Fatihah: 2]." Except that Humayd did not mention the Prophet, may Allah bless him and grant him peace.