Section
Whoever unlawfully kills a person whose life is inviolable, whether directly or indirectly, must offer expiation.
This section concerns the expiation for killing. You should know that the expiation for killing is among the stringent expiations. Two other offences share this characteristic: ẓihār (a man likening his wife to a woman permanently forbidden to him in marriage) and sexual intercourse during the daytime in Ramadan by one upon whom fasting is obligatory. Yet the expiation for these two offences differs from that for killing in that they include feeding [the poor], whereas the expiation for killing does not include feeding.
The evidence for this is the saying of Allah, Most High:
“It is not for a believer to kill a believer unless by mistake. Whoever kills a believer by mistake must free a believing slave and pay blood-money to the deceased’s family, unless they waive it as charity. If the slain believer belonged to a people at war with you, then the expiation is the freeing of a believing slave. And if he belonged to a people with whom you have a treaty, then blood-money must be paid to his family and a believing slave must be freed. Whoever cannot find one must fast for two consecutive months, as repentance from Allah. And Allah is All-Knowing, All-Wise.” [al-Nisāʾ 4:92]
His statement: “Whoever unlawfully kills a person whose life is inviolable, whether directly or indirectly, must offer expiation.”
The word “whoever” is a conditional noun, and conditional nouns convey generality. It therefore includes every killer: the minor, the insane person, the free person, the slave, the male, and the female.
As for one who is legally mature and of sound mind, there is no doubt that expiation is binding upon him, due to the saying of Allah, Most High: “Whoever kills a believer by mistake must free a believing slave ...” and so forth.
But if the person is neither legally mature nor of sound mind, then the scholars differ concerning the matter.