Musnad Abu Ya'la al-Mawsili 243:94

On the authority of Abu Musa, he said: A son was born to me, so I brought him to the Messenger of Allah (peace and blessings of Allah be upon him). He named him Ibrahim, performed *tahnik* for him with a date, prayed for blessing for him, and handed him back to me. He was the eldest of Abu Musa’s children.