Jeremiah 6
27 Ref I have made you a tester of metals [and] a fortress among my people; that you may know and try their way.
28 Ref They are all grievous rebels, going about with slanders; they are brass and iron: they all of them deal corruptly.
29 Ref 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.
30 Ref Refuse silver shall men them, because Yahweh has rejected them.