And do ye abide without the camp seven days..... Which was the time that anyone that touched a dead body remained unclean, Numbers 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, Numbers 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.''

Purification of the Warriors, the Prisoners, and the Booty. - Moses commanded the men of war to remain for seven days outside the camp of the congregation, to carry out upon the third and seventh day the legal purification of such persons and things as had been rendered unclean through contact with dead bodies. Every one who had slain a soul (person), or touched one who had been slain, was to be purified, whether he were a warrior or a prisoner. And so also were all the clothes, articles of leather, materials of goats' hair, and all wooden things.

And do ye abide without the camp seven days: whosoever hath killed any person, and whosoever hath touched any slain, purify both yourselves and your captives on the third day, and on the seventh day.

19-24. abide without the camp seven days: whosoever hath killed any person . purify both yourselves and your captives-Though the Israelites had taken the field in obedience to the command of God, they had become defiled by contact with the dead. A process of purification was to be undergone, as the law required (Le 15:13; Nu 19:9-12), and this purifying ceremony was extended to dress, houses, tents, to everything on which a dead body had lain, which had been touched by the blood-stained hands of the Israelitish warriors, or which had been the property of idolaters. This became a standing ordinance in all time coming (Le 6:28; 11:33; 15:12).

31:19-24 The Israelites had to purify themselves according to the law, and to abide without the camp seven days, though they had not contracted any moral guilt, the war being just and lawful, and commanded by God. Thus God would preserve in their minds a dread and detestation of shedding blood. The spoil had been used by Midianites, and being now come into the possession of Israelites, it was fit that it should be purified.