Musnad Abu Ya'la al-Mawsili 4:25

Muhammad ibn Abdullah ibn Numayr narrated to us, Muhammad ibn Bishr narrated to us, Mujammi’ ibn Yahya al-Ansari narrated to us, Uthman ibn Mawhab narrated to us, from Musa ibn Talhah, from his father, who said: I said, "O Messenger of Allah, how should I invoke blessings upon you?" He said, "Say: O Allah, send blessings upon Muhammad as You sent blessings upon Ibrahim; indeed, You are Praiseworthy, Glorious. And bless Muhammad and the family of Muhammad as You blessed Ibrahim and the family of Ibrahim; indeed, You are Praiseworthy, Glorious."