Deuteronomy 20:13-15

New Catholic Bible

¹³ When the Lord, your God, delivers it into your hands, you shall put every man in it to death. ¹⁴ The women, the children, the cattle, and everything else in the city will be plunder to you. You may take as your own the spoil of your enemies that the Lord, your God, has delivered over to you.

¹⁵ This is how you are to deal with all the distant cities, the cities that do not belong to these nations.