His statement, “immediately due,” describes its legal status: if the killer is poor, it remains a debt upon him until Allah grants him means, like his other debts.

In this case, is it permissible for us to give zakat on his behalf?

The answer is yes, because he falls under the generality of Allah’s statement: “and those in debt.” He is indeed in debt. However, he must repent to Allah for what he has done. If we know that he has repented, we may settle his debt from zakat.

His statement, “quasi-deliberate and accidental,” is in the nominative case. It may also be read with shibh in the genitive case, on the basis that the construct noun has been omitted, the intended wording being: “the blood money for quasi-deliberate killing.” However, the well-known rule is that when the construct noun is omitted, the noun governed by it takes its place in grammatical inflection, as Ibn Malik said:

What follows the construct noun takes its place
In inflection when it is omitted;
Yet at times they put what remains in the genitive,
As though what preceded it had not been omitted.

His statement, “upon his ʿāqilah [male agnatic relatives],” ʿāqilah is an active participle derived from ʿaql, meaning blood money. It was called ʿaql because it was customary for the camels paid as blood money to be brought to the place of the slain person’s heirs, made to kneel, and tied with their hobbles. Thus, blood money is called ʿaql, and those who pay it are called the ʿāqilah.

The proof that the blood money for quasi-deliberate and accidental killing is borne by the ʿāqilah is the report recorded in the two Ṣaḥīḥs concerning the two women who fought: one of them threw a stone at the other, killing her and the child in her womb. The Prophet ruled that her blood money was to be paid by the ʿāqilah (1)—that is, the ʿāqilah of the woman who killed her. This is a textual proof from the tradition.