What is the ruling regarding an unmarried man who committed adultery with a divorced woman, and now wishes to marry her after both of them have repented from zina? Is it lawful for him to marry her according to Islamic law?

Adultery is one of the most heinous sins. The punishment for a married person who commits it is stoning. However, Allah accepts the repentance of an adulterer if he abandons the sin, regrets it, resolves not to return to it, and conceals his deed. If a man and a woman repent from adultery, and the woman is not pregnant, there is no objection to their marriage. The description of adultery is removed from them through sound repentance, for the Prophet, peace and blessings be upon him, said: "The one who repents from a sin is like one who never sinned."