When the officers have finished addressing the army, they are to appoint commanders to lead it.
Israel was at this time to be considered rather as a camp than as a kingdom, entering upon an enemy's country, and not yet settled in a country of their own; and, besides the war they were now entering upon in order to their settlement, even after their settlement they could neither protect nor enlarge their coast without hearing the alarms of war.
Commenting on Deuteronomy 20:1-9
And it shall be, when the officers have made an end of speaking unto the people,.... By reciting what the anointed of war said unto them, and by speeches of their own framing, to encourage to the battle; and all were dismissed that had leave to depart, and chose to take it: that they shall make captains of armies to lead on the people; on...
they shall make captains of the armies to lead the people--When the exempted parties have withdrawn, the combatants shall be ranged in order of battle.