Was the marriage valid if the spouses committed the grave sin of fornication and did not repent before marriage? And if it was not valid and they wished to return, would they start from scratch and the husband have three new pronouncements of divorce?

Scholars differ on the validity of the marriage between an adulterer and an adulteress before repentance. The majority consider it valid, while the Hanbalis deem it invalid unless the adulteress repents. This disputed marriage is called a "corrupt marriage" (Nikah Fasid). However, whoever enters into it believing in its validity (which is the case for most people in disputed marriages) is not considered an adulterer. The rulings of a valid marriage, such as the obligation of the dowry, the lineage of the child, and the occurrence of divorce, apply to this marriage.

After a divorce occurs, it is not permissible to investigate the original contract to annul it. Indeed, Sheikh al-Islam Ibn Taymiyyah, Ibn Rajab, and Al-Buhuti stipulated that divorce occurs in a disputed corrupt marriage if its validity was believed at the time of the contract. The husband who deemed it permissible to have sexual intercourse with his wife before the divorce is not allowed to claim the invalidity of the marriage after the divorce. Accordingly, the divorce that has occurred in this case cannot be annulled, and it is not permissible for the wife to return to her divorced husband until she marries another with the intention of permanence. Then, if he divorces her or dies, she may return to her first husband with a new contract.