What is the ruling on slandering (Qadhf) one's own wife when witnessing her adultery during a period when intercourse has not occurred?

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Slandering one's wife is obligatory if a husband witnesses her committing adultery during a period of purity in which he has not had intercourse with her. He must then separate from her until her waiting period (Iddah) concludes. If she gives birth to a child within six lunar months of the adultery, and he is capable of disclaiming paternity, slandering her and disclaiming the child's lineage becomes obligatory. This action is mandated because the child is virtually certainly from the adulterer, and failing to disclaim paternity results in the child being legally attributed to him, leading to inheritance and kinship ties that are impermissible. If the wife confesses to adultery and the husband believes her confession, the ruling is the same as if he witnessed it.