It is permissible for Muslims to marry non-Muslim women who are taken captives without their husbands or whose husbands have been killed, albeit after purification of their womb from their previous husbands which can take place after a monthly cycle. The Holy Prophet’s marriage with Safiyah was in accord with this requirement.
A) The leaders and chiefs of every religion and faith consider themselves to be more obligated than others to adhere to the rules of the religion. It is quite natural and logical on their part to be so. The people cannot follow a leader unless they see him working hard and committed to the principles of the religion. All the divine prophets and even non-divine leaders have been as such. The history of the early period of Islam is replete with instances of struggle, sacrifice and devotion of the Holy Prophet (pbuh) in matters related to worship. He worked harder and made more attempts than his followers. It has been reported that the Prophet, peace be upon him and his progeny, offered so many prayers that feet swelled up. When his companions asked him: “Why are you taking so much trouble? God has made all your life full of forgiveness and blessing.” He would say: “Should I not be a thankful servant?”
B) In social matters also, he was the most hardworking of individuals. He went through a lot difficulties and pains to prove the truthfulness of himself and the righteousness of his religion which he had brought down for mankind. All the commandments brought down by him were from God. He never spoke out of passion and against the divine revelation. He was very much steadfast in establishing the divine laws. He made his best efforts to convince people to believe in One God and in the religion of God until God told him: “Then maybe you will kill yourself with grief, sorrowing after them, if they do not believe in this announcement.”
B) According to the sacred Shari’ah of Islam, it is haram (unlawful) to consummate marriage with married women. However, women who are taken captives by Muslim warriors are an exception and marriage with them is permissible under certain circumstances.
God, the Exalted, has permitted marriage contract with a female captive after one assures she is not pregnant from her first husband provided that there the captive and her husband should be in two different places. If the woman and her husband are taken captives along with each other, she will not be halal for anyone other than her husband. This order is not applicable to the battles fought between two nations even though one of them might be oppressive and transgressor.
C) The Iddah (waiting period) of a female captive is one menstruation and if a woman is pregnant, she must keep away from marrying another man until she gives birth to her child. Thereupon, she can enter into another marriage.
With this preface in mind, we shall now reread the story of the Holy Prophet’s marriage with Safiyah daughter of Huyay bin Akhtab:
The Battle of Khaybar and the reasons behind it are all indicative of Jews’ mischief and treachery to the Muslims’ newly-built establishment. A number of Jews were killed and a few others were taken captives in the Battle. The rest of the story is cited from Tabaqat al-Kubra (230 A.H.), one of the oldest sources on Islamic history:
“Safiyah daughter of Huyay bin Akhtab and one of her cousins were taken captives when Muslim warriors seized al-Qamus, the fortress of Khaybar. The Prophet (pbuh) ordered Bilal to take them along with their luggage. When a Companion of the Prophet (pbuh) heard of Safiyah’s captivity, he approached the Prophet (pbuh) with a suggestion that since she was a lady of Banu al-Nadir, only the Prophet (pbuh) was fit enough to marry her. The Prophet (pbuh) agreed to this suggestion and suggested her that if she accepted Islam, he would grant her freedom. Safiyah readily accepted the suggestion by saying: I have become Muslim and chosen God and His Prophet. The Prophet (pbuh) considered her manumission to be an adequate mahr (dowry). He stayed in Khaybar until Safiyah got purified of her menses. He came out of Khaybar without consummating the marriage.”
It can be concluded from the foregoing explanation and also through reading the accounts in reliable historical and jurisprudential books that:
1. Safiyah had been one of the female captives.
2. Safiyah had been in the state of menses when she was taken captive and after captivity she had been in her waiting period.
3. The Holy Prophet’s marriage with Safiyah had been after the completion of her menstruation and waiting period and it had been with her consent.
Therefore, considering the preface and the ensuing details, the Prophet’s conduct had been in accordance with Islamic commandments. For further information about the reasons behind the permissibility of Muslim men’s marriage with female captives vide question 1076 (site: 2541).
 - Ibn-e Kathir, al-Bedayah wan-Nehayah, vol.6, pg.58, Maktabat al-Ma’aref, Beirut.
 - “Nor does he say (aught) of (his own) Desire.” [Quran: al-Najm, 3].
 - Al-Kahf: 6.
 - And all married women (are forbidden unto you) save those (captives) whom your right hands possess. It is a decree of Allah for you. [Quran: Nisa, 24].
 - See question4981 (site: 5298).
 - Makarem Shirazi, Tafsir Nomouneh, vol.3, pg.333, Darul Kutu al-Islamiyah, Tehran, 1995.
 - See: Waqedi, Al-Maghazi, translated by Mahmud Mahdavi Damghani, pg.481 onward.
 - Muhammad bin Sa’d, Tabaqat al-Kubra, (translated version), vol.8, pg.124.