Numbers 31:19-24 - Purification After Battle
19 Ye, then, pitch outside the camp, for seven days, - whosoever hath killed a person and whoever hath touched the slain, cleanse yourselves (from sin) on the third day and on the seventh day ye and your captives,. 20 Every garment also, and every article of skin and every thing made of goats-hair, and every article of wood, shall ye cleanse (from sin).
21 Then said Eleazar the priest unto the men of the host, who had been to the war: This, is the statute of the law, which Yahweh hath commanded Moses: 22 Surely the gold and the silver, - the bronze the iron, the tin and the lead, 23 whatsoever thing can go into fire, ye shall pass through fire and it shall be clean, only with the water of separation, shall ye cleanse it (from sin). But whatsoever cannot go into fire, ye shall pass through water. 24 And ye shall wash your clothes on the seventh day, and be clean, - and after-wards, shall ye come into the camp.