Musnad Ahmad 658:30

Aswad ibn Amir narrated to us, Isra'il narrated to us, from Jabir, from Amir, from Al-Bara' ibn Azib, who said: The Messenger of Allah (peace and blessings of Allah be upon him) prayed over his son Ibrahim, and he had died while he was sixteen months old. He said: "Indeed, he has someone in Paradise to complete his breastfeeding, and he is a truthful one (Siddiq)."