Committed zinaa with a non-Muslim woman who has now become Muslim, and he wants to marry her

Allaah says (interpretation of the meaning): “And come not near to the unlawful sexual intercourse (zinaa). Verily it is a faahishah (a great sin) and an evil way.” [al-Israa’ 17:32]

Ibn Katheer (may Allaah have mercy on him) said: “Allaah says, forbidding His slaves to commit zinaa, to approach it or to put themselves in situations that may lead to it or tempt them to it: ‘And come not near to the unlawful sexual intercourse. Verily it is a faahishah’ i.e., a great sin, and ‘an evil way’ i.e., a bad way of behaving.”

Imaam Ahmad said: “Yazeed ibn Haaroon told us that Jareer told us that Saleem ibn ‘Aamir told us, from Abu Umaamah that a young man came to the Prophet (peace and blessings of Allaah be upon him) and said: ‘O Messenger of Allaah, grant me permission to commit zinaa.’ The people turned to him and told him off, saying, ‘Ssh!’ The Prophet (peace and blessings of Allaah be upon him) said: ‘Come closer,’ so he came closer. He told him, ‘Sit down,’ so he sat down. He asked him, ‘Would you like this for your mother?’ He said, ‘No, by Allaah, O Messenger of Allaah. May Allaah cause me to be sacrificed for you!’ He said: ‘No people would like it for their mothers.’ He asked him, ‘Would you like this for your daughter?’ He said, ‘No, by Allaah, O Messenger of Allaah. May Allaah cause me to be sacrificed for you!’ He said: ‘No people would like it for their daughters.’ He asked him, ‘Would you like this for your sister?’ He said, ‘No, by Allaah, O Messenger of Allaah. May Allaah cause me to be sacrificed for you!’ He said: ‘No people would like it for their sisters.’ He asked him, ‘Would you like this for your paternal aunt?’ He said, ‘No, by Allaah, O Messenger of Allaah. May Allaah cause me to be sacrificed for you!’ He said: ‘No people would like it for their paternal aunts.’ He asked him, ‘Would you like this for your maternal aunt?’ He said, ‘No, by Allaah, O Messenger of Allaah. May Allaah cause me to be sacrificed for you!’ He said: ‘No people would like it for their maternal aunts.’ The Prophet (peace and blessings of Allaah be upon him) put his hand on him and said: ‘O Allaah, forgive him his sin, purify his heart and make him chaste.’ After that, the young man never paid attention to anything of that nature.”

Allaah says (interpretation of the meaning): “And those who invoke not any other god along with Allaah, not kill such life as Allaah has forbidden, except for just cause, nor commit illegal sexual intercourse – and whoever does this shall receive the punishment. The torment shall be doubled to him on the Day of Resurrection, and he will abide therein in disgrace; except those who repent and believe, and do righteous deeds, for those, Allaah will change their sins into good deeds, and Allaah is Oft-Forgiving, Most Merciful. And whosoever repents and does righteous good deeds, then verily, he repents towards Allaah with sincere repentance.” [al-Furqaan 25:68-71]

It is not permitted for a man guilty of zinaa to marry a woman who is similarly guilty unless both of them repent sincerely to Allaah, may be He be glorified, so that they will no longer be described as being guilty of zinaa. Allaah says (interpretation of the meaning): “Let no man guilty of adultery or fornication marry any but a woman similarly guilty, or an unbeliever: not let any but a such a man or an unbeliever marry such a woman: to the Believers, such a thing is forbidden.” [al-Noor 24:3]

So you must repent sincerely to Allaah, and follow this kabeerah (major sin) with many good deeds, so that Allaah may forgive you. If you are both sincere in your repentance and adhere to the laws of Allaah from now on, there is nothing wrong with your marrying her. Allaah forgives the one who repents.