And if they come to us afterward, or the spouses embrace Islam, and the woman is lawful for him, they are left in their marriage; but if she is among those whom it is not permissible to marry in the first place, they are separated. …
His statement, “And if they come to us afterward”: that is, after the contract has been completed among them and she has become his wife, they come to us seeking judgment concerning this marriage. We then consider: if the wife is now lawful, we leave the marriage as it stands; but if she is not lawful, we annul the marriage.
For example, if this wife were a woman whom he had divorced three times, and they believe that a thrice-divorced woman is lawful for her former husband, whereas our Sacred Law prohibits this, then, if they come to us, we annul the contract, because the woman is not lawful for him, and we separate them. Likewise, if he were a Magian who had married his sister, and they brought their case before us after the contract, we would not uphold the marriage, because the woman is not lawful for him. When we judge between them by the Book of Allah, we say: “This woman is forbidden to you, so separation is required.” Thus, we separate them in every case.
If it is assumed that she embraces Islam while he remains a disbeliever, we separate them. If they bring their case before us after the contract, having contracted the marriage without a guardian, yet regarding this as valid under their own law, we do not separate them, because the marriage is valid: she is now lawful for him, were he to contract a new marriage with her.
Accordingly, we uphold the marriage, because the principle is that we do not interfere with their previous contracts. Rather, we consider their present circumstances: if they are in a state in which it would be lawful for the husband to marry the woman, we leave the marriage in place; otherwise, we annul it. Even if he married her during her waiting period, and marriage during the waiting period is invalid according to Islamic law, yet is not invalid according to their law, then if they bring their case before us after the waiting period has ended, we uphold it. This is because the principle is: “If the wife is one whom he could validly marry now, we uphold the marriage; otherwise, we do not.”
The same applies if both spouses embrace Islam: we consider whether the woman would now be lawful for him to marry. If so, we uphold their marriage, and if