The answer: If it is most likely, in their judgment, that this is the case, they may testify; but they must exercise the utmost care, lest they fall into a knowingly false oath. Such an oath is one in which a person swears falsely in order to unlawfully take the property of a Muslim. So what then of one who, by it, takes the life of a Muslim?! Therefore, the heirs of the slain person must verify the matter with the greatest care; only when the circumstantial evidence is as clear to them as the sun may they swear.
His statement: “If someone is accused of killing without any lawth, he takes a single oath and is cleared,” is like all other claims. For example, a man claims that so-and-so killed his deceased relative, but there is no lawth. The defendant says, “I did not kill him.” We then say to the claimant, “Do you have evidence?” If he says, “Yes,” we say, “Produce it,” and we rule according to what the evidence entails. If he says, “No,” we say to the defendant, “Swear once: ‘By Allah, I did not kill this man,’” after which he is cleared. But if the defendant refuses to swear, is judgment given against him or not?
The answer: If the legal consequence of the offence is financial liability, judgment is given against him on account of his refusal to swear. But if the legal consequence of the offence is retribution, judgment is not given against him merely because he refuses to swear.
Thus, if the claimant says that he killed him deliberately—an intentional offence entails retribution—and the defendant says, “I did not kill him,” we say to him, “Swear.” If he says, “I will not swear,” we say: We do not rule anything against you, because the offence entails retribution, and retribution is not imposed on the basis of refusing to swear. For if we were to rule against him on that basis, we would kill this person who has refused to swear, since ruling against him on the basis of refusal means that we grant the claimant what he has claimed. Thus, if we were to rule against him on the basis of refusal here, we would kill him; and a human life is sacred and immensely significant—it is not