Deuteronomy 20:5-8

And the officers. — The shôterim of Deuteronomy 16:18; the civil magistrates apparently. The organisation of Israel was not military, but military leaders were to be appointed for special services, as appears by Deuteronomy 20:9, “they shall make captains of the armies.” The captains of thousands, hundreds, fifties and tens were called shôterim (Deuteronomy 1:15).

(5-8) What man is there... — These questions show that, primarily, all Israelites of military age (20 to 50) were expected to attend the muster; then those who were unprepared for the campaign were suffered to depart. The only recorded instance of the observance of these rules is in Judges 7:3, at the muster of Gideon’s army. The proclamation “Whosoever, is afraid let him depart,” sent away 22,000 out of 32,000 on that occasion, or rather more than two-thirds of the army!