This is Not Ash-Shighar

Question :

Five years ago, my paternal uncle came to my father in order to seek his approval for the marriage of my sister, Hissah to his son, 'Ali and they all agreed including my sister. They decided upon the dowry and the conditions, but before leaving the meeting, my uncle said to my father: "What do you think, O Abu Ahmad, if your son Ahmad desires to marry my daughter, 'A'ishah, then we agree." And he meant by this that the whole of his family agreed to it, including his daughter, 'A'ishah. Could we find a better man for our girl than Ahmad? Bearing in mind that we (I mean myself and my family) did not request this from him, that is, we did not say to him: "We will give our daughter in marriage to you on condition that you give your daughter in marriage to our son, Ahmad," but it was my uncle who touched on this subject by his own free will and choice.

So my father did nothing but asked my opinion regarding my uncle's words and if I agreed to marry his daughter, 'A'ishah. I answered my father, saying: "Yes, I agree to marry my uncle's daughter, and I want her as my wife." So both marriages took place within one month, and all praise and thanks be to Allah I and my wife are both happy, and Allah has blessed us with three children. Likewise, my sister and her husband are happy all praise and thanks be to Allah and Allah has blessed them with two children. My question is: Is this marriage valid, or is it considered Ash- Shighar, bearing in mind that the dowry and the conditions of my sister are similar to the dowry and conditions of my wife, except in some very minor details? Benefit me (with advice) regarding the ruling on this and may Allah benefit you.

Answer:

If the situation is as you have described in the question, then this is not a form of Nikah Ash-Shighar and there is no sin in it all praise and thanks be to Allah. Because Ash-Shighar is when a man says to another man: "Marry me to your daughter and I will give my daughter in marriage to you," or: "Marry me to your sister and I will marry you to my sister," or the like. The marriage which you have described in the question does not contain this condition, so it is not Ash-Shighar. And Allah is the Granter of success.

Source:
Ibn Baz
Fatawa Islamiyah, Vol. 5 Pages 418-419