retaliation is not mandatory, for the reasons we have mentioned. If he kills his son's maternal uncle, and his son's mother inherits the retaliation [or a portion of it, then she dies as a result of the husband killing her or otherwise, and her son inherits from her, the retaliation falls] (13); because what prevents an existing (claim) also causes a newly occurring one to fall, and blood money (diya) becomes mandatory. If a woman kills her husband's brother, and the retaliation or a portion of it devolves to her son, the retaliation falls, whether it devolved to him initially, or transferred to him from his father or someone else; for the reasons we have mentioned.

Section: If one of the parents of a mukatab (an indentured slave) kills the mukatab (14), or a slave belonging to him, retaliation is not mandatory, because the parent is not to be killed for his child, and no retaliation is established for the child against his parent. If the mukatab purchases one of his parents and then kills him, no retaliation is mandatory upon him, because the master is not to be killed for his slave.

Section: If there are two sons, one of whom kills his father and the other his mother, and if the marital bond between them existed at the time of the first killing, then retaliation is mandatory upon the killer of the second (victim) and not the first; because the second victim inherited a portion of the blood of the first, so when he was killed, the killer of the first inherited it, and thus he came to possess a portion of his own blood, so the retaliation for it fell, and retaliation became mandatory for him against (15) his brother. If he kills him, he inherits from him if he has no other heir; because he killed (16) him rightfully. And if he pardons him in exchange for blood money, it becomes mandatory, they settle the accounts between them, and whatever remains to one of them is due from him to his brother. If the marital bond between the parents was not subsisting, then upon each one of them is retaliation for his brother, because he inherited the one his brother killed, exclusively without his killer. If one of them acts quickly and kills his companion, he has fulfilled his right, and the retaliation falls from him; because he inherits from his brother [by virtue of it being a killing] (17) by right, so it does not prevent inheritance, unless the victim has a son, or a grandson who would exclude the killer; in which case he has the right to kill his uncle, and he inherits from him if (18) he has no heir other than him. If they dispute over who is to begin