Musannaf Ibn Abi Shayba 3:6258

Ahmad ibn Abdullah narrated to us, he said: Zuhayr narrated to us, he said: Muhammad ibn Ishaq narrated to us, he said: Muhammad ibn Ibrahim ibn al-Harith narrated to me, from Muhammad ibn Abdullah ibn Zayd, from Uqbah ibn Amr, who said: A man came to the Messenger of Allah (may Allah bless him and grant him peace) until he sat between his hands and said: "O Messenger of Allah (may Allah bless him and grant him peace), as for the greeting upon you, we have already learned it. But as for the prayer (salat), inform us how we should pray upon you." He said: The Messenger of Allah (may Allah bless him and grant him peace) remained silent until we wished that the man who asked him had not asked him. Then he said: "When you pray upon me, say: O Allah, send prayers upon Muhammad, the unlettered Prophet, and upon the family of Muhammad, as You sent prayers upon Ibrahim and upon the family of Ibrahim. And bless Muhammad, the unlettered Prophet, and the family of Muhammad, as You blessed Ibrahim. Indeed, You are Praiseworthy, Glorious."