Celibacy and castration are forbidden, as is marrying two sisters, or a woman and her aunt (paternal or maternal), whether he marries the aunt after marrying her niece or vice versa, for fear of breaking the ties of kinship.
It is forbidden to make deals in marriage, such as saying "Let me marry your daughter and I will give you my daughter or sister in marriage." Such reciprocal deals are a form of oppression and injustice, and haraam.
Islam forbids mut'ah (temporary marriage), which is a marriage contract for a period of time agreed by the two parties, at the end of which the marriage expires.
Islam forbids intercourse with a menstruating woman, until she has purified herself (by taking a bath after her period ends), and also forbids anal intercourse.
A man is forbidden to propose marriage to a woman when another man has already proposed to her, unless the other man withdraws his proposal or gives him permission.
It is forbidden to marry a previously-married woman without consulting her, or a virgin without seeking her permission.
It is forbidden to wish (a newly married couple) "Bi'l-rafaa' wa'l-baneen (a joyful life and many sons)," because this is the greeting of the people of Jaahiliyyah, who hated daughters.
The divorced woman is forbidden to conceal what Allah has created in her womb (if she is pregnant).
A husband and wife are forbidden to speak (to others) about the intimacies of married life.
It is forbidden to turn a woman against her husband or to take divorce lightly.
It is forbidden for a woman to ask for another's divorce, such as asking a man to divorce a woman so that she can marry him.
A wife is forbidden to spend her husband's money without his permission, or to keep away from his bed without good reason, because the angels will curse her if she does that.
A man is forbidden to marry his father's wife, or to have intercourse with a woman who is pregnant from another man.
It is forbidden for a man to practise azl (coitus interruptus) with his free wife without her permission. It is forbidden for a man to return home from a journey late at night and startle his family, unless he has previously notified them when he will arrive home.
A man is forbidden to take anything of his wife's mahr (dowry) without her consent, or to keep annoying his wife so that she will give up her wealth.
Islam forbids women to make a wanton display of themselves (tabarruj). It also forbids extreme forms of female circumcision.
Women are forbidden to admit anyone into their husband's home without his permission; his general permission is acceptable so long as they stay within the limits of shari'ah.
It is forbidden to separate a mother and child (in case of divorce); to let one's womenfolk behave foolishly (in an immoral fashion) and not say anything; to let one's gaze wander everywhere; and to follow an accidental glance with an intentional glance.
