Question: I am a young man, twenty years old. I have asked for the hand of my cousin. Because I also have a sister who is of marriageable age, my uncle has refused to let me marry his daughter unless I agree to let his son marry my sister in exchange. I have tried repeatedly to convince him that such an arrangement is impermissible, but to no avail—he is adamant. Under this pressure, and because I very much want to marry his daughter, I have consented to the reciprocal marriage: his son would wed my sister and I would wed his daughter. Up to now, however, the marriages have not yet been concluded. What is the ruling if they are carried out in this manner? If it is impermissible, what should we do so that my marriage and his son’s marriage can be contracted without committing anything unlawful?

Answer: The marriage you describe—where the woman’s guardian refuses to marry her to you unless you marry your sister to his son—is not permissible, because it is a shighar marriage, and such a marriage is invalid.

Whenever the marriage of one woman is made conditional upon the marriage of another, that is shighar. If no dowry is stipulated, it is unanimously agreed among the scholars that the contract is void. Even when a dowry is named, the sounder opinion is that the arrangement is still unlawful, for it harms the two women in favor of the men, and harming women is not allowed. The guardian is obliged to look after the woman’s interest, not his own; he is her guardian and caretaker, and he is not permitted to exploit her vulnerability and his guardianship over her for his personal benefit when that harms her.

Therefore, the arrangement you have mentioned is impermissible; you must not go forward with it, nor may a contract be concluded on that basis. My advice is that you look for another wife whose guardian does not make your sister’s marriage to his son a condition. “Whoever is mindful of Allah, He will make a way out for him, and will provide for him from where he never imagined” (Qur’an 65:2–3).