Deuteronomy 20:13-15

New Revised Standard Version, Anglicised

¹³ and when the Lord your God gives it into your hand, you shall put all its males to the sword. ¹⁴ You may, however, take as your booty the women, the children, livestock, and everything else in the town, all its spoil. You may enjoy the spoil of your enemies, which the Lord your God has given you. ¹⁵ Thus you shall treat all the towns that are very far from you, which are not towns of the nations here.