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.
31:7 All the males - Namely all who lived in those parts, for colonies of them, were sent forth to remoter places, which therefore had no hand either in their former sin, or in this present ruling. And herein they did according to God's own order concerning such people, Deu 20:13, only their fault was, that they did not consider the special reason which they had to involve the women in the destruction.
31:13 Without the camp - Partly to put respect upon them, and congratulate with them for their happy success; and partly to prevent the pollution of the camp by the untimely entrance of the warriors into it.
31:17 The little ones - Which they were forbidden to do to other people, Deu 20:14, except the Canaanites, to whom this people had equaled themselves by their horrid crimes, and therefore it is not strange, nor unjust, that God, the supreme Lord of all mens lives, who as he gives them, so may take them away when he pleaseth, did equal them in the punishment. Every woman - Partly for punishment, because the guilt was general, and though some of them only did prostitute themselves to the Israelites, yet the rest made themselves accessary by their consent or approbation; and partly, for prevention of the like mischief from such an adulterous generation.
31:20 Your raiment - Namely, your spoil and prey. All work - All which had contracted some ceremonial uncleanness either from the dead bodies which wore them, or the tents or houses where they were, in which such dead bodies lay, or from the touch of the Israelitish soldiers, who were legally defiled by the slaughters they made.
31:27 Two parts - The congregation hath some share, because the warriors went in the name of all, and because all having been injured by the Midianites, all were to have some share in the reparations: but the warriors who were but 12000, have a far greater share than their brethren, because they underwent greater pains and dangers.
31:29 An heave - offering - In thankfulness to God for their preservation and good success.
31:30 One of fifty - Whereas the former part was one of five hundred; the reason of the difference is, partly, because this was taken out of the peoples portion, whose hazards being less than the others, their gains also in all reason were to be less: partly because this was to be distributed into more hands, the Levites being now numerous, whereas the priests were but few.
31:50 An atonement - For their error noted, Nu 31:14,15,16, and withal for a memorial, or by way of gratitude for such a stupendous assistance and deliverance. We should never take any thing to ourselves in war or trade, of which we cannot in faith consecrate a part to God, who hates robbery for burnt - offerings. But when God has remarkably preserved and succeeded us, he expects we should make some particular return of gratitude to him.