Musannaf Ibn Abi Shaybah 22952 — Selling umm walad slave women

It is narrated from Sayyiduna Ali (may Allah be pleased with him) that Sayyiduna Umar (may Allah be pleased with him) consulted me about the sale of an umm walad. My opinion and his was that when an umm walad gives birth to a child, she will be freed after her master's death. Sayyiduna Umar (may Allah be pleased with him) ruled accordingly during his lifetime, and after him Sayyiduna Uthman (may Allah be pleased with him) also ruled accordingly. Then, when I became Commander of the Faithful after them, I considered it better to make her a slave woman.