He replied:

Yes. If the man who was promised payment killed him under these circumstances, he is liable to retaliatory execution. The slain person’s heirs have the choice: they may have him executed, accept blood money, or pardon him. As for the man who promised payment, he must receive a punishment that deters him and others like him from such conduct. Some scholars hold that he too is liable to retaliatory execution.

He was asked—may Allah have mercy on him:

If a man deliberately kills his own child, who receives the child’s blood money?

He replied:

If an heir, whether the father or someone else, deliberately kills the person from whom he would inherit, he inherits neither any of that person’s property nor any of his blood money, by agreement of the imams. Rather, the blood money is treated like the rest of the deceased’s property: the killer, whether the father or someone else, is barred from inheriting it, and the remaining heirs inherit it instead.

He was asked—may Allah have mercy on him:

About a man who quarreled with someone, then returned home and became weak. As death approached, he called witnesses to his declaration that so-and-so was his killer. He was asked, “How did he kill you?” but gave no explanation. Is the accused liable to anything or not, given that the sick man bore no sign whatsoever of fatal injury or beating, and many upright witnesses testified that the accused had neither struck him nor done anything to him?