Jeremiah 6:27-30

I have made thee a trier and a fortress among my people; that thou mayest know and try their way. They are all grievous revolters, going about with slanders; they are brass and iron: they all of them deal corruptly. The bellows blow fiercely; the lead is consumed of the fire: in vain do they go on refining; for the wicked are not plucked away. Refuse silver shall men call them, because Jehovah hath rejected them.