not. This is open to question, because if the son has intercourse with her, she becomes one of his consorts and is therefore unlawful to his father. Likewise, according to the preferred view, it is not lawful for a father to have intercourse with his son’s slave woman unless he first intends to take ownership of her. As for having intercourse with her while intending that she remain the property of the son, this is unlawful, for Allah says: “except with their wives or those in their possession” [al-Maʿārij 70:30]. But let us suppose that he has intercourse with his son’s slave woman under a mistaken assumption; she then becomes a mother of a child.
If someone were to ask, “Why does she become a mother of a child when she is not his property, even in the case of intercourse under a mistaken assumption?” They reply: “Because a father is entitled to take whatever he wishes from his son’s property. Since he is entitled to take ownership of her, she is regarded as though she were his property.”
His statement, “his child is created free,” means that the child was conceived free. This excludes the case in which a man marries a slave woman, has intercourse with her, and she becomes pregnant, after which he purchases her. In that case, she does not become a mother of a child, because the child in her womb was not conceived free; rather, it was conceived as a slave belonging to her master. Thus, the child must have been conceived free—that is, she conceived him while she was owned by the master who had intercourse with her.
His statement, “whether born alive or dead, provided that the human form has become discernible,” means that, whether she gives birth to it alive or dead, the form of a human being must have become discernible in it: its hands, feet, and head must be distinguishable. This only occurs after the pregnancy has reached eighty days. Before that, it cannot be formed, because the embryo in its mother’s womb is a drop of fluid during the first forty days, then a clinging clot during the second forty, and then, during the third forty, a formed and unformed morsel of flesh. Therefore, the shaping of its features cannot begin until after eighty days. After eighty days, it may be formed, and by ninety days it is generally formed.