Quran simply acknowledges POW laws that were practiced throughout Middle East, and that is why the Talmud also has “Beautiful Captive” laws.
Please see, “The Spirit of Jewish Law,” George Horowitz, page 151:
“The law with respect to a beautiful woman captured in battle was explained by the Rabbis as intending to prevent licentiousness, acts of rape on the field of battle, etc. for the captor must bring the woman ‘to his house’ (V. 12) and must make her a member of his family (Kiddushim 21b). He must permit her to mourn her parents for one month. And R. Akiva adds in the Talmud that through her religion may have been pure idolatry, she is to be permitted to mourn even loss of her religion (Yevamot 48b). Once having married her as commanded ‘she shall be thy wife’ v. 13), the husband-captor may not use her as a slave, nor treat her with less respect than any other wife. A captor, moreover, may not take such a beautiful captive for any other person (like a relative), but only for himself.”
In the Jewish tradition, only the “beautiful captives” (good looking female virgins) were saved. As the Old Testament testifies, everybody else was killed. In the Arab/Islamic laws of war, if there was no treaty for the exchange of prisoners, all POWs were made slaves but then a month was given to the enemy to pay ransom/reparations in order to free their people. During this time, the women were left untouched. The POWs themselves, if rich, could also offer money to buy their freedom.
In the ancient Middle East, soldiers were encouraged to bring along their women, so they would fight like hell,, because everybody knew that in case of defeat, their women would become captives of enemy soldiers.
In the Arab/Islamic tradition, the women who were captured on the battlefield were distributed by the Chief or head of the State. So some girls could be given to aged men or women who would simply treat them as maids or give them in marriage to other slaves or freemen, as several Hadiths suggests. Male slaves could also be given to free women to work as servants, and. free women could also marry a male slave. Slaves could also work over time to make money or start business on the side to raise money for their freedom. Prophet Muhammad praised a man who would educate a captured slave girl and marry her off to a free man or another slave. By his own example, the Prophet also taught that a woman should not be touched without her consent; if a woman said, “I seek God’s protection from you,” she was left unharmed.
The following are some examples that should prove to you that all of Prophet Muhammad’s relationships were consensual:
“…it is said the he [Prophet Muhammad] proposed to Safiyyah bt. Bashshamah [not to be confused with Safiya Bint Huyay], sister of the one-eyed al-Anbari. She was taken as a captive, so allowed her to choose between him and her husband. She chose her husband, and he sent her back.” The History of al-Tabari, Volume IX, page 140.
“The Messenger of God married Ghaziyyah bt. Jabir of the Banu Abi Bakr b. Kilab. [The news of] her beauty and skill had reached the Messenger of God, se sent Abu Usayd al-Ansari al-Saidi asking her hand in marriage. Being in a state of infidelity when she came to the Prophet, she said, ‘I was not consulted [about this marriage], and I seek refuge from you in the name of God.” He replied, ‘One who seeks God’s protection is inviolable,’ and returned her to her people.” The History of al-Tabari, Volume IX, pages 136-37.
So, it’s clear from this evidence that like David and Solomon. Prophet Muhammad liked women and had many wives but he never forced himself on any woman.
As I stated above, these things were dependent on having or not having a treaty for the exchange of prisoners. If there was a treaty, such a Geneva Convention today, then Muslims were obliged to abide by it. There is no requirement in Islam that POWs be abused or killed. On some occasions, Prophet Muhammad simply freed POWs out of plain goodwill, and Muslims have followed that tradition since ancient times.
Quran and Hadith make no distinction between a Muslim slave and a non- Muslim slave. The only difference is that according to one hadith, freeing a Muslim slave can save a person from hellfire. That does not mean that freeing non-Muslims is not meritorious or is not recommended for expiation of sins. Since, later, a law was established that no free Muslim would be taken as slave, limiting emancipation to Muslims would have been meaningless.
Verse 47:4 of Quran clearly suggests that non-Muslim captives who were made slaves can be freed as a “favor.” In the Battles of Hunain and Bani Mustaliq, non-Muslim slaves were freed. Tabari also lists several non-Muslims who were bought and freed by Prophet Muhammad (s.a.w) or freed when they were captured after a militarycampaign and they fell in his lot. People who were freed by the Prophet (s.a.w) included Yasar, Abu Muwayhibah, and Abu Kabshah, among others. Caliph Umar bin Abd al-Aziz had ordered that non-Muslim subjects, if taken prisoners by an enemy should be as much ransomed and liberated on state expenses as any Muslim subject [for reference see Ibn Sa’ad’s al- Tabaqat al-Kubra, Volume 5, pages 26, 272. For secondary reference see “Non-Muslims Under Sharia’ah Law” by Abdul Rehman Doi).
Verse 4:92 states:
[4.92] And it does not behoove a believer to kill a believer except by mistake, and whoever kills a believer by mistake, he should FREE A BELIEVING slave, and blood-money should be paid to his people unless they remit it as alms; but if he be from a tribe hostile to you and he is a believer, the freeing of a BELIEVING SLAVE (suffices), and if he is from a tribe between whom and you there is a covenant, the blood-money should be paid to his people along with the freeing of a BELIEVING SLAVE; but he who cannot find (a slave should fast for two months successively: a penance from Allah, and Allah is Knowing, Wise.
The verse deals with a specific condition in which a Muslim is found guilty of manslaughter for killing another Muslim. In the verse prior to this, it is clear that what is being referred to is unintentional killing of a Muslim, who may or may not be a hypocrite or who may be living in enemy territory. And if life of a Muslim was taken without proper justification, it was only right that another Muslim benefits and he/she gains freedom. Freeing of a Muslim slave as a compensatory corrective measure does not in any way negate the general principle that freeing of slaves, regardless of their faith, is a meritorious act. In other verses of the Quran, expiation of other sins is achievable through freeing of a slave, and no mention is made whether the slave has to be a Muslim or not. See Verses 90:13, 5:89, 58:03, 9:60, 2:177, 24:33.
To further clarify, in case of a non-Muslim victim of manslaughter at the hands of a Muslim or vice versa, other punishments or penalties may be given. The verse in question was strictly dealing with manslaughter of a Muslim by another Muslim in times of conflict, and under normal circumstances a judge should come up with proper verdict in other cases, including freeing of a non-Muslim slave, if possible. Since slavery no longer exists, other measures may be prescribed to inculcate repentance. Regarding protection of non-Muslims, the Prophet once said “Their property is like our property and their blood is like our blood” (see Mishkat al-Masabih, Ch. 25, Hadith 10). Caliph Ali (r.a.) had also stated, “The blood of a Dhimmi (protected non-Muslim) is like the blood of a Muslim, his goods and chattels are like those of the Muslims.”
One Hadith states:
Book 009, Number 3604:
Abu Huraira (Allah be pleased with him) reported: I heard Allah’s Messenger (may peace be upon him) as saying: He who emancipates a BELIEVING SLAVE. Allah will set free from Fire his every limb for every limb of his (slave’s), even his private parts for his.
The Hadith simply implies that freeing a Muslim slave is such a supererogatory act that a person can save himself from hellfire. It does not mean that freeing a non-Muslim slave does not have its own rewards. Most of the other Ahadith and Quran do not make a distinction between a Muslim and a non-Muslim slave when manumission of a slave is recommended for expiation of sins.