Render it:
I have set thee among My people as a prover of ore,
And thou shalt know and try their way.
They are all of them rebels of rebels (i. e., utter rebels):
Slander-walkers, were copper and iron,
Corrupters all of them.
The bellows glow: from their fire lead only!
In vain hath the smelter smelted,
And the wicked are not separated.
Refuse-silver have men called them:
For Yahweh hath refused them.
The intermixture throughout of moral words and metallurgical terms is remarkable.