the general meaning of His words, exalted is He:
“A life for a life.” [al-Ma’idah 5:45]
It is also based on the general meaning of the Prophet’s saying: “The blood of a Muslim man is not lawful except in one of three cases: a life for a life” (1); and his saying: “The believers’ blood is equal” (2); as well as the specific case of the Prophet’s execution of a Jewish man for a woman. The Prophet executed a Jewish man for a woman after he had crushed her head between two stones because of some silver ornaments she possessed. She was asked, “Who killed you? Was it so-and-so, or so-and-so?” until the Jewish man was mentioned to her, whereupon she nodded her head in affirmation. The Jewish man was then brought, and he confessed. So the Prophet ordered that his head be crushed between two stones (3).
If you ask: Might it not be that the Prophet executed him because he had violated the covenant?
The answer is: No. Had the Prophet executed him for violating the covenant, he would have executed him with the sword. Rather, he executed him by way of retaliation, because he had crushed her head between two stones.
If you ask: Might it not be said that this man’s superiority as a male was offset by his being a disbeliever, while the woman was Muslim; and that, had he been Muslim, he would not have been executed for her?
The answer is that since he was executed by way of retaliation, this establishes that the effective cause is equivalence in retaliation. Thus, merely because he killed deliberately, he is executed.
If you ask: Is not the male superior?
The answer is: Yes, but the Sacred Law has not taken this superiority into consideration.