Ċ O you who believe! When the believing women come unto you as emigrants, examine them. God knows best their faith. Then if you know them to be believers, do not return them to the disbelievers. Those women are not lawful for those men; nor are those men lawful for those women. And give them what they have spent. There is no blame upon you if you marry them when you have given them their bridewealth. And hold not to the ties of disbelieving women. Ask for what you have spent, and let them ask for what they have spent. That is the Judgment of God; He judges between you. And God is Knowing, Wise.
10 This verse discusses the legality of marriage between Muslims and people of other communities, forbidding marriage between Muslims and disbelievers (see also 2:221). Examine them means that when women come to embrace Islam, the Muslims
must first be sure that they have migrated to Madinah out of sincere belief, not out of enmity toward their husbands or because they were enamored of other men (JJ). God knows best their faith indicates that, once they have taken an oath, their word is to be trusted and the matter is between them and God. Though marriage between believers and disbelievers is forbidden, in 5:5, one of the last verses to be revealed, marriage between Muslim men and women from among the People of the Book (i.e., Jews and Christians) is permitted; see 5:5c.
This verse was reportedly revealed after the Treaty of Ḥudaybiyah in 6/628, which stipulated that the Makkans who fled to the Prophet should be returned to the Makkans, but that anyone among the Prophet’s Companions who fled to the people of Makkah would not be returned to Madinah. A Qurayshī man whose wife had joined the Muslims then went to the Prophet and said, “O Muhammad, return my wife to me, for you have agreed to return to us whosoever flees to you.” Then this verse was revealed stipulating that Muslim women could not be married to idolaters and that their return was excluded from the treaty. And give them what they have spent stipulates that any bridewealth that had been paid to the Muslim women before they left their disbelieving husbands in order to embrace Islam must be returned to their disbelieving husbands when they are removed from wedlock with them. The Prophet therefore allowed the believing women who had migrated to Madinah to stay and sent back to the Quraysh the men who had fled the Quraysh to join the Muslims in Madinah (Q, W).