What should a couple do if the husband claims he had anal intercourse with his wife, and the wife vehemently denies it, and the matter escalated into a quarrel that ended with the husband saying, "You are divorced," and should they perform li'an (oath of condemnation), and what are the consequences for them after li'an?

The husband who thought he did something with his wife, confessed his mistake, and repented, the wife should accept his request, and no li'an (oath of condemnation) is necessitated thereby. If he accused her of doing that with someone else, then it is obligatory to believe her and interpret her situation favorably, out of good presumption. The husband must repent for making an accusation based on mere suspicion, and the wife must keep the matter secret. As for the divorce pronounced by the husband, it is a revocable divorce, in which the husband has the right to take her back as long as she is within her iddah (waiting period), without a new contract or mahr (dowry). If her iddah has expired, then there is no marriage except with a new contract and mahr, provided this was the first or second pronouncement of divorce. As for the third pronouncement, she is not permissible for him until she marries another husband.