Musannaf Ibn Abi Shayba 19:794

Abu Bakr narrated to us, he said: Hafs bin Ghiyath narrated to us, from Ash'ath, from 'Adi bin Thabit, from Al-Bara' bin 'Azib: That the Prophet, peace and blessings of Allah be upon him, sent [someone] to a man who had married his father's wife, and he ordered him to bring him his head.