Deuteronomy 20:1-9 The Israelites were not to be afraid when they went to war, regardless of how stronger the enemy was, because God was with them. God directed the High Priest shall give a speech prior to going into battle to remind the Israelites that God was on their side. Before going into a battle, a man may return to his home to dedicate his new house, eat the fruit of his new vineyard, marry his betrothed wife, or if he is too scared to fight.
Notes: The role of the priest in battle was to encourage the soldiers by God’s promise, presence, and power to be strong in faith. A lack of trust in God’s ability to fight for them would affect the strength of their will so that they would become fainthearted. Victory was linked to their faith in God. Anyone whose heart was not in the fight should not be there. Those who had other matters on their minds or were afraid were allowed to leave the army and return to their homes, since they would be useless in battle and even influence others to lose courage.
Deuteronomy 20:10-15 When the Israelites first approach a city to battle, they shall offer terms of peace first. If they agree, then the nation shall sell themselves to the Israelites and do forced labor for the Israelites and serve them. If not, then all the males shall die by the sword. The women, children, and livestock shall be kept as spoil for their enjoyment. This was to be done to cities very far away from where the Israelites would settle.
Notes: Cities outside of Canaan were not under the judgment of total destruction, so to them Israel was to offer a peace treaty.
Deuteronomy 20:16-18 The cities where the Israelites shall live fall under a different set of rules. Everything that breathes shall die (The Hittites and the Amorites, the Canaanites and the Perizzites, the Hivites and the Jebusites). The reason for this is so that no one would teach the Israelites their abominable practices for their gods which will cause them to sin against the Lord.
Notes: The Canaanite cities were to be totally destroyed, i.e., nothing was to be spared, in order to destroy their influence toward idolatry.
Deuteronomy 20:19-20 If the Israelites have to besiege a city for a long time, they were not to chop down the trees and use them as tools for battle, although they were allowed to eat its fruit. Only trees that don’t produce food they could cut down so they can build siegeworks against the city until it falls.
Notes: When besieging a city, armies in the ancient world would cut down the trees to build ramps and weapons, as well as facilities for the long siege.