Second: all those jointly entitled to it must agree to carry it out; none of them may act unilaterally. If one of those remaining is absent, a minor, or insane, then his return, maturity, or recovery of reason must be awaited.
Third: when carrying it out, it must be ensured that the offender is not exceeded against. Thus, if retaliation becomes due against a pregnant woman, or against a non-pregnant woman who subsequently becomes pregnant, she is not executed until she gives birth and nurses the child with the first milk, ........................
His statement, “Second: all those jointly entitled to it must agree to carry it out”: if any one of them pardons, retaliation is waived. Even if the one who pardons inherits only one share out of a million, retaliation cannot be carried out. This is due to Allah’s saying: “But if something is waived for a killer by his brother, then there should be a suitable follow-up and payment to him with good conduct” [al-Baqarah 2:178]. “Waived for him” means: for the killer; “by his brother” means: the slain person; and “something” is an indefinite term occurring in the context of a condition, and thus includes any portion whatsoever. Therefore, if the killer is pardoned even for the slightest part, there can be no retaliation, due to Allah’s saying: “then there should be a suitable follow-up”: the killer is to be pursued for payment in a proper manner and not harmed. And His saying, “and payment to him,” means: to the one who pardoned, “with good conduct.” Payment is one of the characteristics of blood money.
As for the reasoning, it is that if any part of the killer’s life is pardoned, killing cannot be divided into portions. Thus, if there are six heirs and one of them pardons, it is not possible for us to kill five-sixths of the killer and leave one-sixth alive! Since some part of the killer must remain alive, and that part cannot live except with the survival of the rest, the pardon of some of the heirs prevents execution.
His statement, “None of them may act unilaterally”: if those entitled to retaliation are three brothers, and the eldest says, “I am the eldest,” then acts on his own and kills the killer, this is forbidden for him and unlawful. He must be subject to discretionary punishment. If the heirs of the first slain person say, “We have no benefit in his being disciplined; rather, we want the blood money,” they are entitled to that. They may claim the blood money from the offender’s estate, and the offender’s heirs may then recover from the brother who killed him whatever was taken from them, because he is the one who caused them to forfeit it.