“Of every tribe a thousand, throughout all the tribes of Israel, shall ye send to the war.”
King James Version (KJV)
31:3 Avenge ye the Lord - For the affront which they offered to God, by their own idolatry and lewdness, and by seducing God's people into rebellion against him. God's great care was to avenge the Israelites, #Nu 31:2|, and Moses's chief desire was to avenge God rather than himself or the people.
31:5 Twelve thousand - God would send no more, though it is apparent the Midianites were numerous and strong, because he would exercise their trust in him, and give them an earnest of their Canaanitish conquests.
31:6 Them and Phinehas - Who had the charge not of the army, as general, (an office never committed to a priest in all the Old Testament) but of the holy instruments, and was sent to encourage, and quicken, them in their enterprize. The holy instruments - The holy breast - plate, wherein was the Urim and Thummim, which was easily carried, and very useful in war upon many emergent occasions.