And do ye abide without the camp seven days..... Which was the time that anyone that touched a dead body remained unclean, Num 19:11,

whosoever hath killed any person; as most of them if not all must have done; all the males of Midian that fell into their hands being slain by them, that were men grown:

and whosoever hath touched any slain; as they must to strip them of their garments, and take their spoil from them:

purify both yourselves and your captives, on the third and on the seventh day; which were the days appointed for the purification of such that were polluted by touching dead bodies, Num 19:11 and their captives, which were the female little ones; (for as for the women, and males among the little ones, they were ordered to be slain;) though they were Heathens, yet inasmuch as they were to be for the service of the Israelites, and to be brought up in their religion, they were to be purified also; to which purpose is the note of Jarchi;"not that the Gentiles receive uncleanness and need sprinkling, but as ye are the children of the covenant, so your captives, when they come into the covenant, and are defiled, need sprinkling.''

And Moses was wroth with the officers of the host--The displeasure of the great leader, though it appears the ebullition of a fierce and sanguinary temper, arose in reality from a pious and enlightened regard to the best interests of Israel. No order had been given for the slaughter of the women, and in ancient war they were commonly reserved for slaves. By their antecedent conduct, however, the Midianitish women had forfeited all claims to mild or merciful treatment; and the sacred character, the avowed object of the war (Num 31:2-3), made their slaughter necessary without any special order. But why "kill every male among the little ones"? It was designed to be a war of extermination, such as God Himself had ordered against the people of Canaan, whom the Midianites equalled in the enormity of their wickedness.