Musnad Ahmad 32:1736

Muhammad ibn Ja‘far narrated to us, he said: Sa‘id narrated to us, from Qatadah, 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]."