Numbers 31:19-24 - Purification After Battle
19 And encamp ye outside the camp seven days. Whoever has killed any person, and whoever has touched any slain, purify yourselves on the third day and on the seventh day, ye and your captives. 20 And as to every garment, and all that is made of skin, and all work of goats' [hair], and all things made of wood, ye shall purify yourselves.
21 And Eleazar the priest said to the men of war who went to the battle, This is the statute of the law which LORD has commanded Moses: 22 only the gold, and the silver, the brass, the iron, the tin, and the lead-- 23 everything which may go into fire--ye shall make to go through the fire, and it shall be clean. Nevertheless it shall be purified with the water for impurity. And all that may not go into fire ye shall make to go through the water. 24 And ye shall wash your clothes on the seventh day, and ye shall be clean, and afterward ye shall come into the camp.