I have committed adultery, is it permissible for me to repent?

All praise be to Allah and peace be upon the Messenger of Allah, upon his family, his Companions, and those who follow him.

Fornication is one of the major sins and the prohibition of fornication is well-known in Islam as well as other religions. All the people of the Scriptures as well as all reasonable people hold consensus for its prohibition because it was not made lawful in any legislation. Allah warned us against fornication by His Saying: "And come not near to unlawful sex. Verily, it is a Fâhishah (i.e., anything that transgresses its limits: a great sin), and an evil way (that leads one to Hell unless Allâh forgives him)." [Surat Al Isra': 32].

Therefore, its prescribed punishment was the severest amongst all prescribed punishments because it is an aggression against honors and lineage.

You and that man have to repent to Allah sincerely because the one who repents sincerely to Allah his repentance shall be accepted and his past sins shall be forgiven as Allah (He may be Glorified) says: "And He it is Who accepts repentance from His slaves, and forgives sins, and He knows what you do." [Surat Ash-Shura: 25].

Allah (may He be Exalted) said after He had threatened those who commit the most grievous sins with His Saying: "Except those who repent and believe (in Islâmic Monotheism), and do righteous deeds; for those, Allâh will change their sins into good deeds, and Allâh is Ever Oft-Forgiving, Most Merciful." [Surat Al Furqan: 70].

When Allah knows the sincerity of those who repent, He accepts their repentance, forgives their sins, and erases their faults. Allah (may He be Exalted) says: "Say: O 'Ibâdî (My slaves) who have transgressed against themselves (by committing evil deeds and sins)! Despair not of the Mercy of Allâh: verily, Allâh forgives all sins. Truly He is Oft-Forgiving, Most Merciful." [Surat Az-Zumar: 53].

Ibn Majah reported on the authority of Ibn Mas`ud (may Allah be pleased with him) that the Prophet (peace be upon him) said: "The one who repents of his sins is like those who have no sin." Ibn Hajar graded it as good. As for your marriage from that man with whom you have committed that crime, Scholars differed about the validity of that marriage: The majority of scholars adopted the view that it is valid, however Imam Ahmad adopted the view that the marriage is prohibited until they repent because of Allah's Saying: "Bad statements are for bad people (or bad women for bad men) and bad people for bad statements (or bad men for bad women). Good statements are for good people (or good women for good men) and good people for good statements (or good men for good women): such (good people) are innocent of (every) bad statement which they say; for them is Forgiveness, and Rizqun Karîm (generous provision i.e., Paradise)." [Surat An-Nur: 26].

There is no harm to marry after sincere repentance is done, and marriage cannot be concluded before repentance; this is the preponderant view which Shaykh Al Islam Ibn Taymiyah chose: "The marriage of the adulteress is forbidden until she repents whether she will marry the one with whom she committed adultery or another; this is the most correct view of a group of the Pious Predecessors and Successors including Imam Ahmad and others, whereas many of the Pious Predecessors permitted that kind of marriage which is the view of Imam Abu Hanifah, Ash-Shafi`y, and Malik."

Ibn Qudamah said in Al Mughny: "If a woman commits adultery, it is not permissible for the one who knows about that to marry her except for two conditions:

1- The elapse of her `Iddah (the waiting period after divorce).

2- To repent of adultery, and this is the view of the majority of scholars."