Numbers 31:21-23

New Catholic Bible

²¹ Then Eleazar said to the men of war who had gone into battle: “This is a statute of the law which the Lord has commanded Moses: ²² gold, silver, brass, iron, tin, lead, ²³ and anything else that can withstand fire will be pure if you pass it through fire. However, it must also be purified with the water of purification. Whatever cannot withstand fire must pass through water.