Deuteronomy 20:15-20

15 This is the way you deal with the distant towns, the towns that don't belong to the nations at hand.

16 But with the towns of the people that God, your God, is giving you as an inheritance, it's different: don't leave anyone alive.

17 Consign them to holy destruction: the Hittites, Amorites, Canaanites, Perizzites, Hivites, and Jebusites, obeying the command of God, your God.

18 This is so there won't be any of them left to teach you to practice the abominations that they engage in with their gods and you end up sinning against God, your God.

19 When you mount an attack on a town and the siege goes on a long time, don't start cutting down the trees, swinging your axes against them. Those trees are your future food; don't cut them down. Are trees soldiers who come against you with weapons?

20 The exception can be those trees which don't produce food; you can chop them down and use the timbers to build siege engines against the town that is resisting you until it falls.

Deuteronomy 20:15-20 Meaning and Commentary

INTRODUCTION TO DEUTERONOMY 20

In this chapter rules are given to be observed in times of war. When a battle was near, a priest was to address the soldiers, and encourage them to fight, De 20:1-4, then the officers were to declare who might return home, De 20:5-9 when an enemy's city was approached, peace was to be proclaimed on certain conditions, which, if accepted of, the inhabitants were to be tributaries and servants, but if not, when taken, all were to be put to the sword, excepting women, children, and cattle, De 20:10-15, but those of the seven nations were to be utterly destroyed, De 20:16-18, and, during a siege, no trees bearing fruit fit for food were to be cut down, De 20:19.