Musannaf Ibn Abi Shayba 3:618

Abu Bakr narrated to us, he said: Usama narrated to us, from Ibn ‘Awn, from Ibrahim: Alqama used to teach a Bedouin the Tashahhud. Alqama would say: "Peace be upon you, O Prophet, and the mercy of Allah, and His blessings, and His forgiveness." The Bedouin would repeat it. Alqama said: "This is how we were taught."