In Islam, fornication and adultery are grave sins and committing either bears serious consequences in this world and the hereafter. However, in a practical and matchless approach to prevent the crime of zina before its occurrence, Islam does not merely forbid the actual deeds, but Islam also declares each and every circumstance or avenue that may lead to fornication and adultery as forbidden. Allah Almighty says, “And come not near unto adultery. Lo! it is an abomination and an evil way.” (Al-Isra’: 32)
But those who commit this sin should not lose hope in Allah’s forgiveness as long as they repent and are determined to correct their lewd conduct. In fact, Islam encourages them to get united in marriage to have a lawful relationship particularly if their relationship results in pregnancy.
Elaborating on this, we’d like to cite for you the fatwa issued by the Egyptian Darul Ifta’ (House of Fatwa):
“It is unanimously agreed that an adulterer/or fornicator is allowed to marry the adulteress/or the fornicatrix he impregnated. If she gave birth to a child six months after the marriage, the child is legitimately his. If the child is born less than six months after the marriage, it is not, unless the man admits that the child is his, even if he does not disclose having an affair with the woman. This admission is held as an evidence of the adulterer’s fathering the child for the probability of a previous marriage. The wisdom behind that is to secure a Muslim’s best interest and attempt to preserve the woman’s honor.
Concerning the marriage of a man who never engaged in adultery/or fornication to an adulteress/or fornicatrix, opinions varied. Al-Hasan Al-Basri holds that adultery invalidates marriage, whereas the majority of scholars maintain that a Muslim may marry an adulteress. These differences may be traced back to the following verse: “Let no man guilty of adultery or fornication marry any but a woman similarly guilty, or an Unbeliever: nor let any but such a man or an Unbeliever marry such a woman: to the Believers such a thing is forbidden.” (An-Nur: 3)
The former opinion depends on the literal meaning of the verse which voices total prohibition. Conversely, the latter view interprets the verse as meaning marrying an adulteress is just blameworthy, but not forbidden. They base their view on the hadith that states: “The lawful action is not rendered unlawful by a sinful act.” (Reported by Ibn Majah on the authority of Ibn `Umar and by Al-Bayhaqy on the authority of `A’ishah)
The majority of scholars, however, differ as regards the details. If the adulteress/or fornicatrix is not pregnant, a non-adulterer/or a non-fornicator may marry her. If she is, Abu Hanifah and Muhammad maintain that he can marry her provided that he does not consummate the marriage until she delivers, because of the following evidence:
Firstly, an adulteress is not listed among the women a Muslim is prohibited to marry. A Muslim can, therefore, marry her. Allah, Exalted be He, says, “Lawful unto you are all beyond those mentioned…” (An-Nisa’: 54)
Secondly, the illegal sexual relation has no significance in Shari`ah. This is confirmed by the fact that the illegitimate child is not ascribed to the adulterer/or fornicator, as the hadith states: “The (illegitimate) child is ascribed to the woman who begets him/or her, and the penalty for prostitution is stoning (to death).” So long as the illegal sexual relation has no significance, it does not render marriage to the adulteress/or fornicatrix unlawful. The reason behind forbidding having sexual intercourse with a pregnant adulteress/or fornicator until she delivers is revealed by the Prophet’s words, “Whoever believes in Allah and Judgment Day is not to water another man’s plant,” i.e. have sex with the woman who got pregnant by illicit affairs.
Abu Yusuf and Zufar indicate: A pregnant adulteress cannot get married because pregnancy prevents engaging in sexual intercourse, which, in turn, prevents contracting marriage. So just as a non-adulteress pregnant woman cannot get married, a pregnant adulteress cannot either.
According to the Maliki jurists, a Muslim is not allowed to marry an adulteress/or fornicatrix before she is cleared of the adultery/or fornication, by waiting for three menstrual cycles or three months. Contracting marriage before that is illegal and must be annulled, whether the woman turns out to be pregnant or not. If she is, marrying her is unlawful because of the above-mentioned hadith. If she is not, a Muslim is still not allowed to marry her before the waiting period is over in order to avoid confusion concerning the father of any potential child.
The Shafi`i jurists maintain: Should a man commit adultery with a woman, he is allowed to marry her, as Allah, Exalted be He, says, “Lawful unto you are all beyond those mentioned…” (An-Nisa’: 54) and also because of `A’ishah’s previously mentioned hadith.
The Hanbali jurists maintain: If a woman commits adultery/or fornication, a Muslim who knows of that is not to marry her except under two conditions: Firstly, her `Iddah (the waiting period necessary before getting married) must be over. If she conceives a child out of wedlock, her `Iddah comes to an end upon delivery and she is not to get married before that, because of the aforementioned hadith, “Whoever believes in Allah and Judgment Day is not to water another man’s plant.” This view is held by Malik. Secondly, the adulteress/or fornicatrix should repent of her sin; this is based on the verse, “All that is forbidden unto believers.” (An-Nur: 3) It is thus unlawful to marry her before she repents. Should she repent, a Muslim is no longer prohibited to marry her as the Prophet (peace and blessings be upon him) says, “Whoever repents of his sin is absolved of it as if he never sinned.” However, the rest of the Jurists do not stipulate this condition.”