four witnesses. If he fails to produce those witnesses, he is liable to the prescribed punishment for slander—eighty lashes—as the Almighty says: “Those who accuse chaste women and then fail to bring four witnesses, flog them with eighty lashes” (Sūrah al-Nūr 24:4).

An exception to this general ruling occurs when a husband accuses his own wife of adultery. In principle he must still furnish proof—namely, four witnesses—to back his claim. If he cannot provide the four witnesses, the penalty for slander is lifted through the procedure of liʿān: he swears four times that he is telling the truth in what he has alleged against her, and on the fifth oath he calls Allah’s curse upon himself if he is lying.

The rationale is that when a man beholds such indecency in his wife he cannot stay silent, as he might if he saw it in a stranger, for the matter is a disgrace to him, a public shame, and a violation of his honor. Indeed, no one would dare accuse his own wife unless he were certain, for only an overpowering sense of protective jealousy could impel him to do so—since the dishonor affects them both. This, therefore, strengthens the likelihood that his allegation is true.