What did Allah order when the pagans refused to pay what the Muslims had spent on the wives who emigrated to Islam from the pagans, according to the hadith narrated by Az-Zuhri, which Prophet Muhammad (saw) implemented?
  Narrated Az-Zuhri:                      `Urwa said, "Aisha told me that Allah's Apostle used to examine the women emigrants. We have been told also that when Allah revealed the order that the Muslims should return to the pagans what they had spent on their wives who emigrated (after embracing Islam) and that the Mushriks should not. keep unbelieving women as their wives, `Umar divorced two of his wives, Qariba, the daughter of Abu Urhaiya and the daughter of Jarwal Al-Khuza`i. Later on Mu'awiya married Qariba and Abu Jahm married the other." When the pagans refused to pay what the Muslims had spent on their wives, Allah revealed: "And if any of your wives have gone from you to the unbelievers and you have an accession (By the coming over of a woman from the other side) (Then pay to those whose wives have gone) The equivalent of what they had spent (On their Mahr)." (60.11) So, Allah ordered that the Muslim whose wife, has gone, should be given, as a compensation of the Mahr he had given to his wife, from the Mahr of the wives of the pagans who had emigrated deserting their husbands. We do not know any of the women emigrants who deserted Islam after embracing it. We have also been told that Abu Basir bin Asid Ath-Thaqafi came to the Prophet as a Muslim emigrant during the truce. Al-Akhnas bin Shariq wrote to the Prophet requesting him to return Abu Basir.