How can a couple who committed adultery and repented, and who wish to hasten their marriage to avoid falling into sin again, get married, and how do they know that their repentance has been accepted?

Adultery is one of the major sins that necessitate immediate repentance. It is not permissible for a Muslim man to marry an adulteress until she repents and is cleansed by one menstrual cycle or by giving birth if she is pregnant. If the two fiancés repent from adultery, it is permissible for him to marry her with a valid contract. She is considered a stranger to him until the contract is concluded. Sincere repentance from a sin, which involves seeking forgiveness, feeling remorse, and abandoning the sin, is accepted by the will of Allah, as Allah the Almighty says: "And He is the one who accepts repentance from His servants and pardons sins, and He knows what you do."