Musannaf Ibn Abi Shaybah 24610 — A man who frees a slave

It is narrated from Sa'd bin al-Akhram that a man came to Sayyiduna Ibn Mas'ud (may Allah be pleased with him) and said: I have freed this slave woman of mine, and I stipulated on her that she serve me as a slave woman serves her master, except for her private parts; or he said: other than the private parts. Then when her neck grew thick (that is, she grew strong), she said: I am free. He said: She has no such right. Take hold of her and go with her, for she must fulfil the condition you stipulated.