Forbidden to you (for marriage) are: your mothers, your daughters, your sisters, your father’s sisters, your mother’s sisters, your brother’s daughters, your sister’s daughters, your foster mothers who gave you suck, your foster milk suckling sisters, your wife’s mothers, your step daughters under your guardianship born of your wives, the wives of your sons, and two sisters in wedlock at the same time. Quran 4:23

In the name of Allah, the Most Gracious, the Most Merciful.

Quran: Chapter 4, ‘Lan Tanalu’ ‘By no means shall you attain’, Sura: 4 ‘An-Nisa’ ‘The Women’, Verse: 23

Verse 23: Forbidden to you (for marriage) are: your mothers, your daughters, your sisters, your father’s sisters, your mother’s sisters, your brother’s daughters, your sister’s daughters, your foster mothers who gave you suck, your foster milk suckling sisters, your wife’s mothers, your step daughters under your guardianship, born of your wives to whom you have gone in- but there is no sin on you if you have not gone in them (to marry their daughters), – the wives of your sons who (spring) from your loins, and two sisters in wedlock at the same time, except for what has already passed; verily, Allah is Oft-Forgiving, Most Merciful.

Notes by samia2010oct: A man cannot marry and cannot have sexual relations with the wives of his father because they are his mothers. Also a man cannot marry and cannot have sexual relations with his daughters, his sisters, his father’s sisters, his mother’s sisters, his brother’s daughters, his sister’s daughters, his foster mothers who gave him suck, his foster milk suckling sisters, his wife’s mothers, his step daughters under his guardianship born of his wives with whom he had sex— but there is no sin if he did not have sex with the mother to marry her daughter. In the later case the man will have to divorce the mother to marry the daughter. Also a man cannot marry and cannot have sexual relations with the wives of his sons. Also a man cannot marry and cannot have sexual relations with two sisters at the same time. If a man’s wife dies he can marry his wife’s sister or he can divorce his wife to marry her sister.

If a man in today’s world, unknowingly and mistakenly married any of the Muharramaat, women a man is forbidden to marry in Islam or married two sisters at the same time, he must quickly divorce one as per Islamic rule, with all the benefits given to a divorcee in Islam.

When a person accepts Islam, he starts enjoying new Islamic life with the change of rules governing his life. Whatever sin he committed in his non Islamic life before Islam, when he enters Islam he must repent the sin, must stop doing it, must compensate for the loss if some one’s right was snatched and must ask for forgiveness from Allah the Most Gracious, the Most Merciful. So those sins are forgiven by Allah provided he repents, stops doing it in his Islamic life, compensates for the loss if he snatched some one’s right and asks for forgiveness from Allah, then the person starts a new life without the burden of before Islam sins.

The same holds true for the born Muslims as well. When they realize their mistake, they stop doing it, repent it, compensate for the loss if they snatched some one’s right and ask for forgiveness from Allah. Allah forgives their sin provided they stop it forever, compensates for the wrong doing and they start a new sinless life according to Islam.

It is Big Sin Gunaahe Kabira for a man to marry or to have sexual relations with the wives of his father because they are his mothers. Also its Big Sin, Gunaahe Kabira for a man to marry or to have sexual relations with his daughters, his sisters, his father’s sisters, his mother’s sisters, his brother’s daughters, his sister’s daughters, his foster mothers who gave him suck, his foster milk suckling sisters, his wife’s mothers, his step daughters under his guardianship born of his wives with whom he had sex. Also its Big Sin Gunaahe Kabira for a man to marry or have sexual relations with the wives of his sons. Also it is Big Sin Gunaahe Kabira for a man to marry two sisters at the same time or to have sexual relations with two sisters at the same time. For Big Sins, Gunaahe Kabira, there is the punishment of unbearable burning of whole body by Unending Fire. At this point we also remember that there are many sins for which the punishment by Allah starts in this world too and this sin is one of them.