Deuteronomy 20:10-15

10“When you approach a city to fight against it, make an offer of peace.

11If it accepts your offer of peace and opens its gates to you, all the people found in it will become forced laborers for you and serve you.

12However, if it does not make peace with you but wages war against you, lay siege to it.

13When the Lord your God hands it over to you, strike down all its males with the sword.

14But you may take the women, dependents, animals, and whatever else is in the city — all its spoil — as plunder. You may enjoy the spoil of your enemies that the Lord your God has given you.

15This is how you are to treat all the cities that are far away from you and are not among the cities of these nations.