Musannaf Ibn Abi Shayba 13:3065

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Sufyan narrated to us: If two men testify against a man that he divorced his wife, then they retract their testimony, he said: The divorce remains [valid] if he had not entered upon her. The husband enters upon them [the witnesses] for half of the dowry. And if he had already entered upon her, then there is nothing upon them, meaning regarding the dowry.