Musannaf Ibn Abi Shayba 13:1805

Abu Bakr narrated to us, he said: Ali bin Mushir narrated to us, from Isma'il bin Abi Khalid, from al-Sha'bi, from Masruq, that he was asked about a man who emancipated a slave of his during his illness, and he had no wealth other than him. He said: "I permit it, for it is something he made for Allah; I will not reject it." And Shurayh said: "I permit a third of him, and I require him to work for his freedom regarding the remaining two-thirds."