First: his statement, “the prescribed punishment and discretionary punishment are waived from him.” Both the prescribed punishment and discretionary punishment are waived from the husband; here, however, the conjunction means “or”—that is, or discretionary punishment. The prescribed punishment applies if the wife is sexually chaste, whereas discretionary punishment applies if she is not sexually chaste. Thus, if the wife is sexually chaste, he incurs the prescribed punishment for false accusation of adultery: eighty lashes, as Allah, Exalted is He, says:
“And those who accuse chaste women, then do not produce four witnesses—flog them with eighty lashes.” [al-Nur 24:4]
If she is not sexually chaste, he is liable to discretionary punishment: the imam is to punish him in a manner that deters him from such conduct, even if he is her husband. The evidence that the prescribed punishment is waived from him is that the Prophet ﷺ did not administer the prescribed punishment to Hilal ibn Umayyah or to Uwaymir al-Ajlani, may Allah be pleased with them; moreover, his testimony is tantamount to legal evidence.
Second: his statement, “separation between them is established.” This is the second consequence of liʿān: the two are separated.
His statement, “separation is established,” outwardly indicates that it does not require the judge to pronounce their separation. That is, the judge need not say, “I have separated you two”; rather, separation between the husband and wife is established merely by the completion of liʿān. And this is indeed the case.
Third: his statement, “through a perpetual prohibition.” This is the third consequence of liʿān: she becomes perpetually unlawful for him. She can never again be lawful for him, whether she marries another man afterward or not, for the following reasons:
First: this is entailed by the previously mentioned proofs: the Messenger ﷺ separated them and declared her unlawful for him.
Second: the rational proof. We say: how can two people possibly be reconciled when one says that the other has committed adultery, while the other says that he is a false accuser and a liar?! There can be no reconciliation between them.