Ан-Ниса 4:93

And whoever slays a believer deliberately, intending to kill him, with something that is lethal, aware of the fact that he [the slain] is a believer, his requital is Hell, abiding therein, and God is wroth with him and has cursed him, He has removed him from His mercy, and has prepared for him a mighty chastisement, in the Fire: this may be explained as [referring to] the person that deems such [killing] licit, or as being his requital if he were to be requited, but it would not be anything new if this threat [of punishment] were to be forgone, because of what He says: Other than that [that is, idolatry] He forgives whomever He will [Q. 4:48]. It is reported from Ibn ‘Abbās that it [the verse] should be understood as it stands, abrogating other verses of ‘forgiveness’. The verse in [sūrat] al-Baqara [Q. 2:178] clearly indicates that the one who kills deliberately should be killed in return, or if he is pardoned then he has to pay the blood-money, the value of which has already been mentioned. It is made clear in the Sunna that between the intentional and the unintentional, there is a type of killing that is identified as [being with] quasi-deliberate intent (shibh al-‘amd), where the killer has slain with what in most cases is not [a] lethal [implement]. In such a case, there is no [right to] retaliation and blood-money is paid instead, so that it [this type of killing] is described as intentional, but [considered] unintentional in [that there applies] the fixing of the period [for payment] and the sharing of the burden [by the killer’s clan]; in this [case] and that of intentional killing redemption is more urgent than in unintentional killing.