(Deut. 20:13-14 NASB) When the LORD your God gives it into your hand, you shall strike all the men in it with the edge of the sword. 14 Only the women and the children and the animals and all that is in the city, all its spoil, you shall take as booty for yourself; and you shall use the spoil of your enemies which the LORD your God has given you.
This passage seems horrific. However, in the very next chapter, we find restrictions on this subject. Deuteronomy 21:10-14 states:
When you go out to battle against your enemies, and the LORD your God delivers them into your hands and you take them away captive, 11 and see among the captives a beautiful woman, and have a desire for her and would take her as a wife for yourself, 12 then you shall bring her home to your house, and she shall shave her head and trim her nails. 13 She shall also remove the clothes of her captivity and shall remain in your house, and mourn her father and mother a full month; and after that you may go in to her and be her husband and she shall be your wife. 14 It shall be, if you are not pleased with her, then you shall let her go wherever she wishes; but you shall certainly not sell her for money, you shall not mistreat her, because you have humbled her.
At first glance, this law seems barbaric, too. Remember, we have no problem admitting that (see principle two above). Furthermore, this is an example of case law (see principle three above), which was a concession –not a command. However, in addition to these already established principles, we can make additional observations:
First, the foreign woman wasn’t raped. This is astonishing, when we consider the culture in the ancient Near East. Military rape was par for the course. The Jews were not permitted to do this.
Second, the foreign woman was given 30 days to grieve. The Jewish soldier couldn’t lustfully take her into bed right away. He had to wait for a full month. In that time, he might change his mind. If the man changed his mind, the woman had to be set free.
Third, widows of war were typically destitute. They were turned into sex slaves, tortured, or killed. In Jewish culture, however, these women were given the dignity of marriage and a home. They weren’t considered sex objects; they were considered spouses. Moreover, if the marriage fell apart, the women could not be sold as slaves (v.14). John Wenham writes, “In a world where there are wars, and therefore prisoners of war, such regulations in fact set a high standard of conduct.” Moreover, in 2 Kings 6:20-23, we read that the Jews would not kill POW’s, because they considered it morally evil.
 Wenham, John William. The Goodness of God. Downers Grove, IL: InterVarsity, 1974. 96.