Sahih Bukhari, Chapter: Conditions

Urwa said, "Aisha told me that Allah's Apostle (SAW) 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 Muslims should not keep unbelieving women as their wives, Umar divorced two of his wives, Qariba, the daughter of Abu Umaiyya and the daughter of Jarwal Al-Khuzai. Later on Muawlya 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 disbelievers..." (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 Mushrikun 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 (SAW) as a Muslim emigrant during the truce. Al-Akhnas bin Shariq wrote to the Prophet (SAW) requesting him to return Abu Basir.