Musannaf Ibn Abi Shayba 3:1121

Abu Bakr narrated to us, he said: Sufyan ibn 'Uyaynah narrated to us, from 'Abd al-Karim, from 'Amr ibn Shu'ayb, who said: When a boy from the Banu 'Abd al-Muttalib began to speak clearly, the Prophet, may Allah bless him and grant him peace, would teach him this verse seven times: "All praise is due to Allah, who has not taken a son, and has had no partner in [His] dominion."