- Al-Mardāwī says in Sharḥ al-Iqnaʿ: Slander (qadhf) is unlawful except in two circumstances:
The first: when a man sees his wife committing fornication during a period of purity in which he has not had intercourse with her—even if the act stops short of full penetration—then abstains from her, and she subsequently gives birth to a child that could reasonably be attributed to the adulterer. In this case he must accuse her of adultery and disclaim the child, because the situation amounts to near certainty that the child was conceived through fornication.
The second: when he sees her committing fornication but she does not bear a child whose denial would be obligatory, or her adultery becomes well known among the people, or a trustworthy person informs him of it, and the like. In these situations, he is not required to accuse her, for he can simply separate from her, and that is preferable to slander since it is more discreet, as noted earlier.