Musannaf Ibn Abi Shayba 19:411

Abu Bakr narrated to us, he said: Sahl ibn Yusuf narrated to us, from ‘Amr, from al-Hasan, regarding four [men] who testified against a man that he had divorced his wife three times, and he denied it, but he admitted to having sexual intercourse with the woman. He said: There is no prescribed punishment (*hadd*) upon him, because he is a disputant.