Jeremiah 6:27-30

“I have made you a tester of metals among my people, that you may know and test their ways. They are all stubbornly rebellious, going about with slanders; they are bronze and iron; all of them act corruptly. The bellows blow fiercely; the lead is consumed by the fire; in vain the refining goes on, for the wicked are not removed. Rejected silver they are called, for the LORD has rejected them.”