Musannaf Ibn Abi Shaybah

Hazrat Umar (may Allah be pleased with him) says regarding a slave woman’s child that her child will set her free, even if the child is not fully developed.

Hazrat Qarib Thaqafi (may Allah have mercy on him) narrates that his father bought a slave girl from a man for four thousand dirhams. This slave girl had miscarried an (incomplete) child from her master. When Hazrat Umar (may Allah be pleased with him) heard of this, he came and raised his whip to strike and said: After your flesh has mixed with her flesh, and your blood has mixed with her blood, do you sell her? May Allah's curse be upon the Jews, for fat was made unlawful for them, so they sold the fat and consumed its price.

Hazrat Hasan (may Allah be pleased with him) says: When a slave woman becomes pregnant by her master, and then her child is miscarried, if the creation of the child is apparent, then she is an umm walad; there is no way to sell this slave woman.

Hazrat Sha'bi (may Allah have mercy on him) says that when the child shows signs of ordinary creation (such as flesh, etc.), then that child will be counted, and his mother will be considered free.

Hazrat Hasan (may Allah be pleased with him) and Muhammad (may Allah have mercy on him) say that if a slave woman miscarries a child from her master, she is free.

Hazrat Zuhri (may Allah have mercy on him) says that an umm walad will be set free when her premature child is miscarried, provided it is known that the child was miscarried prematurely.

Hazrat Hammad states regarding Umm Walad that when she gives birth to a premature child, the slave woman will be considered free.