Musnad Abu Ya'la al-Mawsili 106:43

Abu Bakr narrated to us, Mu'awiyah ibn Hisham narrated to us, Sufyan narrated to us, from Firas, from al-Sha'bi, from al-Bara' who said: Ibrahim, the son of the Prophet (may Allah bless him and grant him peace), passed away while he was sixteen months old. The Messenger of Allah (may Allah bless him and grant him peace) said: "Bury him in al-Baqi', for he has a wet nurse who will complete his nursing in Paradise."