Jeremiah 6:27-30

Amplified Bible

²⁷ 
“I [the Lord] have set you as an assayer [O Jeremiah] and as a tester [of the ore] of My people,
That you may know and analyze their acts.”
²⁸ 
They are all the worst [kind] of [stiff-necked, godless] rebels,
Going around spreading slander.
They are [not gold and silver ore, but] bronze and iron;
They are all corrupt.
²⁹ 
The bellows blow fiercely,
The lead is consumed by the fire;
In vain they continue refining,
But the wicked are not separated and removed.
³⁰ 
They call them rejected silver [only dross, without value],
Because the Lord has rejected them.