Jeremiah 6:28-30

New International Version - UK

²⁸ They are all hardened rebels,
    going about to slander.
They are bronze and iron;
    they all act corruptly.
²⁹ The bellows blow fiercely
    to burn away the lead with fire,
but the refining goes on in vain;
    the wicked are not purged out.
³⁰ They are called rejected silver,
    because the Lord has rejected them.’