Verses 6-12:
Phinehas, the son of Eleazar the high priest, accompanied the army into battle. He was the successor to the office of high priest, and as such was Jehovah’s representative in the battle.
The "holy instruments" likely refer to the furniture of the Tabernacle, primarily the Ark of the Covenant. This later was a custom in Israel, Jos 3:14; 6:8; 1Sa 4:3, which may have begun at this occasion.
The "kings" of Midian were likely the tribal chieftains or heads of clans. Jos 13:21 identifies them as vessels of the Amorite king Sihon. It may be inferred that these were the tribes who gave allegiance to the invaders, and were thus considered traitors to their fellow countrymen. This would explain Israel’s relatively easy victory, as well as the appearance two centuries later of the formidable force of Midianites.
The soothsayer Balaam was slain in this battle, thus reaping the harvest of judgment for his complicity in seducing Israel.
The Israeli army slew the Midianite men in battle, but they took captive the women and children along with their livestock and personal belongings as spoils of war. They burned their cities and "goodly castles," tirah, towers, likely the pastoral villages consisting of tents and crude huts.
"Spoil," shalal, the goods confiscated in battle.
"Prey," malqoach, "what is taken or caught," the livestock, women, and children captured in battle.
"Captives," shebi, prisoners taken in battle.
All captives and booty were taken to Israel’s camp in the plains of Moab.