Numbers 31:21-23

Young's Literal Translation

²¹ And Eleazar the priest saith unto the men of the host who go in to battle, `This [is] the statute of the law which Jehovah hath commanded Moses:

²² only, the gold, and the silver, the brass, the iron, the tin, and the lead,

²³ every thing which may go into fire, ye cause to pass over through fire, and it hath been clean; only, with the water of separation it is cleansed, and all that may not go into fire, ye cause to pass over through water;