Musannaf Ibn Abi Shayba 19:778

Abu Bakr narrated to us, he said: Jarir narrated to us, from Mughira, from Ibrahim, who said: If he divorces her three times, then disowns his child while he does not possess the right of return (raj'ah), he is flogged and the child is attached to him. And if he disowns his child while he possesses the right of return, he performs li'an (imprecation) and the child is disowned from him, even if he had never acknowledged him at all.