What are the women whom a man is eternally forbidden to marry? Is the prohibition limited to reasons of lineage, fosterage, and affinity, or does it also include Ihram and Li'an? And what is the meaning of Ihram and Li'an in this context? Are there specific instances of past actions or words between a man and a woman that could lead to an eternal prohibition of marriage between them?

The women permanently forbidden (for marriage) are of four types: due to lineage, suckling, affinity (through marriage), and mula'anah (mutual imprecation). Some scholars add a fifth type: the wives of the Messenger of Allah, peace and blessings be upon him, based on the Almighty's saying: {And it is not [fitting] for you to harm the Messenger of Allah or to marry his wives after him, ever} [Al-Ahzab: 53].

Regarding a man marrying a woman he previously knew, if it is meant that he committed zina (fornication/adultery) with her, then it is permissible for him to marry her after repentance and ensuring her womb is clear. If something else is meant, please clarify it for an answer.