Deuteronomy 20:14-16

New Revised Standard Version, Anglicised

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. ¹⁶ But as for the towns of these peoples that the Lord your God is giving you as an inheritance, you must not let anything that breathes remain alive.