Musannaf Ibn Abi Shayba 19:375

Abu Bakr narrated to us, he said: Jarir narrated to us, from Mansur, from Ibrahim, regarding a man who performed *li'an* (oath of imprecation) with his wife, and then they were separated, and then he declared himself a liar. He said: He is to be flogged, and the child is to be attributed to him.