Old Testament advice for conquering a city.
And when the Lord thy God hath delivered [a city] into thine hands, thou shalt smite every male thereof with the edge of the sword: But the women, and the little ones . . . shalt thou take unto thyself . . . But of the cities of these people, which the Lord thy God doth give thee for an inheritance, thou shalt save alive nothing that breatheth" (Deuteronomy 20:13-16). "When thou goest forth to war against thine enemies . . . And seest among the captives a beautiful woman, and hast a desire unto her, that thou wouldest have her to thy wife; Then thou shalt bring her home to thine house . . . thou shalt go in unto her, and be her husband, and she shall be thy wife" (Deuteronomy 21:10-13).
Thus, while the men are to be killed, the women and children are to be taken as slaves. Pretty women are to become the wives of conquering men who find them attractive. However, women and children in places the Lord gives His chosen people as an inheritance are to be killed (along with every other living thing).