Jeremiah 6:27-29

New Revised Standard Version, Anglicised

²⁷ I have made you a tester and a refiner^[a] among my people
    so that you may know and test their ways.
²⁸ They are all stubbornly rebellious,
    going about with slanders;
they are bronze and iron,
    all of them act corruptly.
²⁹ The bellows blow fiercely,
    the lead is consumed by the fire;
in vain the refining goes on,
    for the wicked are not removed.