The obligation to repent from the marriage of shighar and to renew the marriage if there is desire

Question: From 'Abd al-'Aziz ibn 'Abd Allah ibn Baz to the honorable brother A. A. M., may Allah guide him. Amen.
Peace be upon you, and Allah's mercy and blessings. As for what follows:
A person came to me who used the initials A. A. M. for his name. He stated that he had proposed to your sister, and I agreed to that on the condition that he would marry you to his daughter. He agreed to that, and the marriage contract was concluded for him with your sister and for you with his daughter, he said. He then sought my legal ruling on the matter.

Answer: I informed him that this contract in this manner is not permissible, because it is a marriage of shighar, which the Prophet (peace and blessings be upon him) forbade. It is called "marriage of exchange" among the Bedouin. It is obligatory for both of you to repent from that and to feel remorse for what occurred, if what occurred is as he stated. It is also obligatory for both of you to renew the marriage if each one desires to remain with her spouse, provided that the renewal is without the condition of exchange for either one. However, if they do not desire to remain with their spouses, it is obligatory to divorce them with a single pronouncement of divorce. You do not owe a mahr if you have consummated the marriage with his daughter, just as he does not owe a mahr if he has consummated the marriage with your sister, because each one is entitled to what was paid to her for what was made lawful of her private parts. You mentioned that you did not consummate the marriage with his daughter. Therefore, if she does not desire to renew the marriage with you, she is not entitled to a mahr. If anything in the matter is unclear to you, come to me or to the honorable Judge 'Afi'f, or to another judge, to ask about what is unclear to you. May Allah guide everyone to what pleases Him, and peace be upon you, and Allah's mercy and blessings.