Jeremiah 6:27-29

Amplified Bible, Classic Edition

²⁷ I [says the Lord] have set you [Jeremiah] as an assayer and a prover of ore among My people, that you may know and try their doings and be like a watchtower.

²⁸ They are all the worst [kind] of rebels and utter and total revolters against God, going about publishing slander. They are [not gold and silver ore, but] bronze and iron; they are all corrupters.

²⁹ The bellows blow fiercely, the lead is consumed by the fire; in vain do they continue refining, for the wicked [the dross] are not removed.