He replied:

As for the traveler who was wrongfully killed, the bandit who killed him must be executed in retaliation, provided the requisite conditions are met. As for the second man who was wrongfully killed, if his life was legally protected, then the person who identified him must be executed in retaliation if he deliberately lied. If he was mistaken, blood money must be paid by his kin group responsible for such payments, if he has one; otherwise, he himself must pay it.

As for the man who killed him, if he did not kill him deliberately but did so in error, the heirs may claim blood money from him or his kin group. However, if he is held liable for the blood money, he has recourse against the person who identified the victim or that person’s kin group, since, in cases such as this, the killing is attributed to the person who identified him. For this reason, he must be executed if he deliberately lied, just as witnesses must be executed if they retract their testimony and say, “We deliberately lied.” Allah knows best.

He—may Allah have mercy on him—was asked:

A man killed someone whose father and mother were still alive. They waived their right to retaliation against the killer and drew up a written undertaking stipulating that he must neither enter their territory nor reside there, and that, should he reside there, he would again be answerable for their son’s blood. If he does reside there, may they demand retaliation for the killing, or not?

He replied:

Praise be to Allah. If they pardoned him on this condition and he failed to fulfill it, the pardon is not binding. Rather, according to some scholars, they may demand blood money from him; according to another opinion, they may demand his execution in retaliation.

This applies whether the condition is considered valid or invalid, and whether its invalidity is considered to invalidate the agreement or not, for those two opinions rest on these principles.