had anyone among the nations maintained that a wrongful, transgressing killer should never be put to death. No human being held this view; rather, all humanity agrees that, as a general rule, a killer is put to death. Yet powerful oppressors distinguish between one slain person and another.
Some interpret His words:
“In legal retribution there is life for you”
as meaning that, when a would-be killer knows he will be put to death, he refrains, thereby preserving both his own life and that of his intended victim. The response to this is: this meaning is sound, but everyone knows it, and it is ingrained in human nature. No human being permits someone to be killed without his killer being put to death. Rather, everyone allows the killer to be put to death when the two are equal. Nor can it be imagined that people … (1) if anyone who could overpower another killed him without himself being put to death, would settle for money.
Since this principle is among the first things human beings recognize, and they know that they cannot live without it, it is comparable to their need for food, drink, and shelter. The Quran is too exalted for its purpose to be merely to acquaint people with such self-evident matters. Rather, this is included within its meaning: when He prescribed legal retribution for those slain, whereby one free person is offset against another, one slave against another, and one female against another, He made the blood-money for one equal to that for the other, and the blood of one equivalent to that of the other. This entails their equality in matters of blood and blood-money. Through this offsetting of claims, their lives are preserved from the strife that would bring about their destruction, as is well known.
This meaning can be derived from this verse. Thus, it is understood that the blood and blood-money of one free person are equivalent to those of another free person, so one is put to death for killing the other. And once it is understood that claims are offset because the amounts of blood-money are equal, it is understood that blood-money is due for the slain person.