Musannaf Ibn Abi Shayba 19:377

Abu Bakr narrated to us, he said: Abu Bakr ibn Ayyash narrated to us, from Mutarrif, who said: If a man accuses his wife of adultery (qadhf), he performs li'an (imprecation) with her. If he subsequently declares himself a liar, he is flogged, the child is attributed to him, and his wife is returned to him.