Numbers 31:4

Each tribe sent 1,000 men to the battle. This allowed everyone to gain combat experience and share the victory.

Arm some of yourselves--This order was issued but a short time before the death of Moses. The announcement to him of that approaching event [Num 31:2] seems to have accelerated, rather than retarded, his warlike preparations.

And Moses spake unto the people. There is no doubt but that Moses delivered the commands which he had received from God; although, therefore, it is stated [205] that only ten thousand went forth to the war, yet the facts themselves demonstrate that the number, as well as the mode of warfare, was prescribed by God. And assuredly it would have been inconsiderate of Moses to attack so great a people with so small a band; and thus he would have deservedly incurred the penalty of his rashness, if he had attempted it of his own accord; still, when God's command had preceded, he happily concluded the matter, which had been properly and rightly undertaken. Nor can it be questioned but that God desired by this test to prove the faith of His people. For, according to human apprehension, it was folly to endanger themselves without cause; and the objection was obvious that it was by no means advisable, when six hundred thousand men were at hand, to restrict to so few the office of waging such a perilous war. Just, therefore, as God afterwards destroyed the great army of the Midianites by only four hundred men under the guidance of Gideon, so also under the hand of Moses He sent forth only a single thousand from every tribe for the destruction of that nation. The tribe of Zebulon alone could have furnished five times as many soldiers as God took from the whole people. Thus, then, they proved their faith, when in reliance on the aid of God alone, they did not hesitate boldly to rush forward against their enemies. And the event itself more fully illustrated God's grace than as if they had fought with all their forces, for then it would have been believed that the Midianites were overwhelmed by the infinite multitude of men. As, therefore, the people testified their obedience by prompt compliance, so they experienced in the result that there is nothing better than to submit ourselves to God, and to leave the prospect of success so completely in His hand, as that our confidence may depend solely upon him.

Lest either of the tribes should boast itself against the others, they were each of them commanded to give the same number of soldiers. Moreover, Phinehas was sent with them, not so much that he might engage personally with the enemy, or be their General, as that he might rule and control their minds as God's messenger and interpreter. They were to be kept in the fear of God, and to be elevated to the expectation of victory, and therefore God's priest was their leader, so that the war might be a holy one; and the same was the object of the silver trumpets, with which, in obedience to the Lw, as we have elsewhere seen, [206] the Levites were accustomed to sound, that it might be manifest that their battles were not fought without the will and authority of heaven. Amongst "the holy instruments," some commentators, in my opinion rightly, include the Ark of the Covenant.

Of every tribe a thousand,.... So that the whole number of those that were armed were 12,000 as after given:

throughout all the tribes of Israel; this is observed, as Jarchi thinks, to comprehend the tribe of Levi, which in some cases was left out of the account:

shall ye send to the war; to fight with Midian.

To carry out this revenge, Moses had 1000 men of each tribe delivered (ימּסרוּ, see at Num 31:16) from the families (alaphim, see Num 1:16) of the tribes, and equipped for war; and these he sent to the army (into the war) along with Phinehas the son of Eleazar the high priest, who carried the holy vessels, viz., the alarm-trumpets, in his hand. Phinehas was attached to the army, not as the leader of the soldiers, but as the high priest with the holy trumpets (Num 10:9), because the war was a holy war of the congregation against the enemies of themselves and their God. Phinehas had so distinguished himself by the zeal which he had displayed against the idolaters (Num 25:7), that it was impossible to find any other man in all the priesthood to attach to the army, who would equal him in holy zeal, or be equally qualified to inspire the army with zeal for the holy conflict. "The holy vessels" cannot mean the ark of the covenant on account of the plural, which would be inapplicable to it; nor the Urim and Thummim, because Phinehas was not yet high priest, and the expression כּלי would also be unsuitable to these. The allusion can only be to the trumpets mentioned immediately afterwards, the ו before חצצרות being the ו explic., "and in fact." Phinehas took these in his hand, because the Lord had assigned them to His congregation, to bring them into remembrance before Him in time of war, and to ensure His aid (Num 10:9).