Fornication is a heavily punishable sin described as fahisha 24:2,17:32 which includes anything that is abominable, morally reprehensible, in words or deeds. Whether open or concealed, they are to be avoided at all costs 6:151,7:33,29:45. These are acts enjoined by evil spirits 24:21 and the guilty becomes unlawful for marriage with a chaste believer as long as he/she perseveres in such behaviour so that the gross immoral contamination should not spread among the healthy and pious members of the society 24:3,26. When the guilty repents and mends his/her ways then the prohibition is lifted, as denoted with the omission of the titles ‘fornicator’ and ‘fornicatress’ 24:5.
Fornicators are therefore forbidden to marry other members of the Muslim community, just like the idolaters with whom intermariages are prohibited 2:221. The Bible reflects that notion too in Deut7:3,Ezra9:13,2Cor6:14. The Torah further teaches that if a Jewish man marries a gentile woman, he must divorce her, send her away, and send the children who resulted from this illegal union as well.
In Islam a relationship outside the legal limits carries great risks for the ones involved, as well as collateral repercussions which they will have to answer for before God. Besides the prescribed punishment if convicted, neither man or woman are covered by the mutual rights and obligations the Islamic law guarantees in a legal union. That unprotected situation extends to a child eventually born outside a legal union. Neither he nor his biological father may claim the mutual rights and obligations that would have otherwise been compulsory. This includes inability to inherit and no possibility to claim lineage between the biological father and the child. This law is derived from the principle that a child is attributed to the father when it is legitimate for him to be in the bed with the child's mother. The Prophet said
"The child will be attributed to the “bed” and the adulterer will receive the stone".
The stone is a metaphor for receiving nothing. The father is deprived from his child, and the child remains with his mother, from whom he will inherit.
Although technically, neither he nor the child can claim kinship, nothing forces the biological father to turn that child away, or prevents him to care for the child out of love and kindness, as Islam encourages concerning any weak person. Also, the fact that a girl born outside a legal union is not the legitimate child of her biological father, does not entail that they could hypothetically marry. It is forbidden whether she becomes his step-daughter, through marriage with her mother 4:23 or in any other situation. This is the majority view, derived from the detailed version of the prophet's hadith about the bed and the stone. In it the prophet determined through resemblance that a boy whom Sawda bint Zamaa assumed was her biological brother, was in fact not her biological brother. He was technically her brother, since born from her father's slave girl, but biologically he was the son of another man. The prophet thus told her to observe the veil in his presence, because he is now non-mahram. This means that biological lineage of a person, whether legitimate or not, determines his/her status as mahram (not marriageable) or non mahram (marriageable). Included as non marriageable daughters in the verse 4:23 are therefore those born from legitimate or illegitimate unions.
Among the jurists, opinions vary on the legal ramifications of the status of an illegitimate child. For example if a couple marries after committing adultery, and that the biological father does not legally disown the child (lian), then the child is considered his if it is proven that the interval between the legal union and the delivery is at least 6 months.
Ibn Taymiyah reported a view according to which the hadith of the bed and the stone is interpreted as speaking of fornication with a married woman. This is more in congruence with the complete version of the hadith, as stated earlier, where a man claimed a child who was born to the slave girl of another man. Ibn Taymiyah said the following:
"There are also two views among the scholars concerning the zaani claiming the child as his if the woman is not married. The Prophet said: “The child is to be attributed to the husband and the adulterer deserves nothing.” So he said that the child belongs to the husband, not the zaani. But if the woman is not married then this hadeeth is not applicable".
Abu Haneefah equally said:
If a man commits zina with a woman and she gets pregnant from him, I do not see anything wrong with him marrying her even though she is pregnant, so as to conceal her (sin), and the child will be his child".
As to social stigma, although it certainly exists, as in any society, it is however not endorsed by the teachings of Islam. An illegitimate child has the same social and religious rights and obligations as any other Muslim. Any hadith pointing to the opposite is weak, or misinterpreted. For example when asked about a child of adultery, Aisha responded that he/she has nothing of the sin of the parents, citing the Quran 6:164 (see also 17:15,35:18,39:7,53:38). She said this in comment to the report where the prophet said "The child of adultery is worst of the three".
‘Urwah narrated: It reached ‘Aisha that Abu Huraira related that the Messenger of Allah said, “The child of adultery is worst of the three.” She said, “May Allah have mercy on Abu Huraira, he erred at hearing and erred at relating it; the hadith was not in this meaning. Actually there was a man who hurt the Messenger of Allah and it was mentioned to the Prophet that besides what he had done he was also born out of adultery. Thus the Messenger of Allah said, “He is worst of the three.”
The prophet here is not pointing to the illegitimacy of the child as the sin. Rather he described him as he was known, but condemned his action as worse than that of his biological parents who committed adultery. Aisha's remark highlights a known flaw in hadith approach, which is to read a report in ignorance of context, knowledge of the vast corpus of reports so as to establish patterns, and knowledge of the Quran. There is no such notion in Islam of inheriting sin like a disease. An illegitimate child does not transfer that status to his progeny. That is why the scholars have pointed that the expression "waladu zinya" doesnt literally mean “child of adultery”, rather refers to one whose major trait is this type of sin
"The Prophet said: [He who is] Waladu zinya, he who casts up the favours on others, he who is disobedient to his parents and he who is addicted to drinking, will not enter Paradise".
Such mode of expression is amply found in Arabic, including in the Quran where for instance the traveller is called ibn al sabil/son of the road. It is found in many other languages, including in the NT where Jesus called his Jewish opponents "children of the devil". And as to the apparent restrictions recommended by some jurists as regards illegitimate children, like marrying them, accepting their testimony, or leadership are all precautionary in nature, not absolute. They take into account their possible unstable upringing as a factor of difficulty to them. If they are found to be qualified, stable or good mannered then the same opportunities are allowed to them as with a legitimate child.
As a point of comparison, the Bible and Jewish tradition state that the mamzer status, which is that of someone born of an illicict relationship, excludes a person from the lineage of the biological father and neither can the father claim him as his child. That status is hereditary, forbidding the mamzer and his or her descendants from marrying an ordinary (non-mamzer) Jewish spouse Deut23:3. Further, the laws of incest do not give a direct injunction against "uncovering the nakedness" in front of one's own daughter Lev18. In the context of legal sexual relations, implied by "uncovering the nakedness", the passage lists what is intended by "close relatives one may not approach naked", and surprisingly, a man's daughter is absent from the list.
