Abu Hanifah and a group of scholars held that no expiation is due from a minor or an insane person. They said: This is because expiation is a right due to Allah, not a purely financial obligation, in view of the Prophet’s saying: “The Pen has been lifted from three” (1)—among whom are the minor and the insane person. Expiation is therefore not binding upon them, because they are not legally accountable.
Is a sleeping person like the minor and the insane person? That is, if a woman falls asleep on her child without realizing it, and the child dies, must she offer expiation?
The answer is yes: she must offer expiation, even though the Pen has been lifted from her. This is because she is among those legally accountable; sleep is an impediment, not the absence of a requisite condition. In contrast, in the case of the minor and the insane person, a requisite condition is absent. As for the sleeping woman, the relevant factor is the presence of an impediment; otherwise, she is legally accountable.
The view of Abu Hanifah is closer to what is correct than the view held by the majority of the scholars, although their position has some basis for consideration. They say that Allah made expiation obligatory for accidental killing, which indicates that intention is not a condition. Legal accountability is required in acts of worship only because sound intention is required, whereas the minor and the insane person have no intention; thus, acts of worship are not obligatory upon them. But intention is not a condition for the obligation of expiation in a case of killing, as demonstrated by its being obligatory upon one who kills by mistake.
This view is very persuasive. However, it may be said that the fundamental obligation of legal accountability does not apply to one who is not legally accountable. In my view, this reasoning is stronger than the reasoning of the majority.