13.—to afflict the soul,] Such as vows of fasting and abstinence, Lev. xvi. 29. Bp. Kidder. See the note there. Chap. XXXI. ver. 2. Avenge the children of Israel] Chap. xxv. 17. Moses is commanded here to "avenge the Israelites;" but ver. 3, he requires the people to "avenge the Lord." The Midianites had brought destruction upon the people of Israel; and had drawn them from God into idolatry; and on both these accounts were obnoxious, as offenders against God, and against Israel. Bp. Kidder. 17. Now therefore kill &c.] Moses gave an order that the boys and the women should be put to death, but that the young maidens should be kept alive. This proceeding shews good policy, combined with mercy. The young men might have become dangerous avengers of, what they would esteem, their country's wrongs; the mothers might have again allured the Israelites to the love of licentious pleasures, and the practice of idolatry, and brought another plague upon the congregation; but the young maidens not being polluted by the flagitious habits of their mothers, nor likely to create disturbance by rebellion, were kept alive. These young women were reserved for the purposes of slavery: a custom, abhorrent from our manners, but every where practised in former times; and still practised in countries, where the benignity of the Christian religion has not softened the ferocity of human nature. Bp. Watson. 19. — purify both yourselves] Such purifications were common among the Gentiles, especially the Greeks; with whom it was the custom, when they had killed a man, to wash their hands in water for the purification of the defilement. Bp. Patrick.