Numbers 31:21-23

21Then the priest Eleazar said to the soldiers who had gone to battle, “This is the legal statute the Lord commanded Moses:

22The gold, silver, bronze, iron, tin, and lead —

23everything that can withstand fire — you are to pass through fire, and it will be clean. It must still be purified with the purification water. Anything that cannot withstand fire, pass through the water.