Notice the following observations which are very different for thinking regarding war today:
1) As we saw above, the decision to wage war against Midian was not made through a consultation of Israelite leaders; it was commanded by Yahweh.
2) They take the vessels of the sanctuary with them: they represent Yahweh’s Presence with them.
3) They treat the Midianites just as Yahweh commands in the book of Deuteronomy for non-Canaanite people: “And when the LORD your God gives it [a city] you’re your hand, you shall put all its males to the sword, but the women and the little ones, the livestock, and everything else in the city, all its spoil, you shall take as plunder for yourselves. And you shall enjoy the spoil of your enemies, which the LORD your God has given you” (Deuteronomy 20:13-14). But Moses gets angry with the leaders because they allowed the women, the cause of the sin at Baal-peor, to live, as well as the boys who possibly lead a rebellion against Israel in the future. Therefore, he commands them to exterminate these two groups.
4) Numbers 31 spends a lot more time discussing the treatment of the captives, the purification of the soldiers and the assimilation of the booty than it spends on narrating the battle itself. Since the battle is a ritual and sacred act, all of these actions are extremely important and open the possibility of contaminating the entire nation if they are not performed in agreement with the law.
5) Remember that when we studied the atonement money in Exodus 30:11-16, we saw that the Israelites received guilt when they were counted in a census, and therefore each one paid an offering of a precious metal to atone themselves. Now we see the same idea in Numbers 31:49-50. They count the soldiers after the battle and discover the miracle that no Israelite soldier died. And since they were counted, they pay the atonement money: “And we have brought the LORD’s offering, what each man found, articles of gold, armlets and bracelets, signet rings, earrings, and beads, to make atonement for ourselves before the LORD” (Numbers 31:50).
All of the conquest of Canaan will be a holy war, but in Numbers 32, it seems like two of the tribes don’t want to participate. The tribes of Reuben and Gad want to settle the land east of the Jordan River, outside the Promised Land, because Israel took it from Sihon and Og and because it is good for cattle-raising. From the petition, “Do not take us across the Jordan” (Numbers 32:5), Moses sees a rebellion just like the one a generation earlier in Numbers 14; he reproves them for disobedience and for discouraging their brothers. But they come to an agreement to accompany their brothers in the conquest of the Promised Land, leaving their families in fortified cities in the meantime. Remember this suspicion of the tribes east of the Jordan; to a certain point, it seems like it will remain hidden and then reappear in Joshua 22.
Numbers 33 looks back and remembers Yahweh’s faithfulness, from Israel’s redemption on Passover night through the journey in the desert until the present time. It mentions places of miracles and national growth like Marah (“Bitter”; Exodus 15:22-26) and Sinai; it mentions places of national shame like Kibroth-hattaava (“Tombs of Covetousness”; Numbers 11:4-35) and Hazeroth (where Aaron and Miriam rebelled against Moses; Numbers 12); it mentions significant events like Aaron’s death and the first contact with the Canaanites under the king of Arad. And the purpose of recalling the past is to encourage the nation to look to the future: “And you shall take possession of the land and settle in it, for I have given the land to you to possess it… But if you do not drive out the inhabitants of the land from before you, then those of them whom you let remain shall be as barbs in your eyes and thorns in your sides, and they shall trouble you in the land where you dwell. And I will do to you as I thought to do to them” (Numbers 33:53, 55-56).
Therefore, the holy battle that was waged against Midian is only the first step of all that they will do in all of Canaan. It serves as one example for the Israelites to follow, all of their tribes united in obedience to Yahweh.