Jeremiah 6:28 in the King James Version
They are all grievous revolters, walking with slanders: they are brass and iron; they are all corrupters.
Context
27 “I have made you a tester of metals and a fortress among my people, that you may know and try their way.
28 They are all grievous rebels, going around to slander. They are bronze and iron. All of them deal corruptly.
29 The bellows blow fiercely. The lead is consumed in the fire. In vain they go on refining, for the wicked are not plucked away.