Musannaf Ibn Abi Shayba 13:1434

Abu Bakr narrated to us, he said: Ghundar narrated to us, from Shu'bah, from al-Hakam, he said: I asked him about a man who hired out his slave for a year and wanted to take him back. He said to him: "He may take him back." He said: And I asked Hammad, and he said: "He shall not take him back except due to harm."