he is not to be killed for him, because a half-free person is not killed for a free person. If one who is half-free kills someone who is half-free, he is to be killed for him; for retaliation occurs between the two totalities without distinction, and they are equal (6).

Section: Retaliation applies between the rulers and governors and their subjects, due to the generality of the verses and reports, and because the believers are equal in their blood, and we know of no disagreement regarding this. It was established from Abu Bakr, may Allah be pleased with him, that he said to a man who complained to him about a governor who had cut off his hand unjustly: "If you are truthful, I will surely extract retaliation for you from him (7)." It was also established that Umar, may Allah be pleased with him, would allow retaliation against himself. Abu Dawud narrated (8), saying: Umar gave a sermon and said: "I have not sent my governors to strike your skin nor to take your wealth. Whoever has been treated in such a way, let him report it to me, and I will extract retaliation for him from him." Amr ibn al-As said: "If a man disciplines one of his subjects, would you extract retaliation from him (9)?" He said: "Yes, by the One in whose hand is my soul, I would extract retaliation from him, for I have seen the Messenger of Allah, peace and blessings of Allah be upon him, allow retaliation against himself." This is because the believers are equal in their blood, and these two are free Muslims, between whom there is no kinship/interbreeding (10), so retaliation applies between them, just like the rest of the subjects.

Section: If someone other than the heir of the victim kills the killer, then retaliation is due upon his killer, and the heirs of the first [victim] are entitled to the blood money from the estate of the first perpetrator. This is the opinion of al-Shafi'i. Al-Hasan and Malik said: His killer is to be killed, and the blood [claim] of the first is nullified; because its subject has passed away, similar to the case of killing the perpetrator slave. It was narrated from Qatada and Abu Hashim: There is no retaliation upon the second; because he killed one whose blood was permissible [to be shed], so no retaliation was necessitated by his killing, like the married adulterer. Our proof for the necessity of retaliation upon his killer is that he is a subject whose killing was not definitively required, and it was not permitted for anyone other than the heir of the victim to kill him, so retaliation was necessitated by his killing, as if he had a debt upon him. Our proof for the obligation of...