EXCHANGE OF DAUGHTERS
During the pre-Islamic days there was a form of marriage in vogue in Arabia under the name of Shighar marriage, (exchange of daughters) which was a manifestation of the absolute authority of the fathers over their daughters. A man would give his daughter in marriage to another man in consideration of the latter giving his daughter in marriage to him. In such a form of marriage neither of the wives would get a dower. Islam abolished this custom. It is worth noting that the Holy Prophet allowed full liberty to his daughter Fatimah Zahra (Peace be upon her) in choosing her husband.
He gave in marriage several other daughters also, but he did not deprive them of their freedom. When Ali Ibn Abi Talib, (peace be on him), approached the Holy Prophet, seeking Fatimah's hand, the Prophet said that several other people had already approached him and that he had conveyed their proposals to Fatimah, but she turned her face away, as a mark of disapproval. The Prophet assured Ali that he would convey to her his proposal as well.
The Prophet went to Fatimah and told his beloved daughter what Ali wanted. This time she did not turn her face away, but kept quiet and thus expressed her consent. When the Prophet came out, he was happy. He exclaimed, "Allah is the Greatest!"
