'Furnace' in the Bible

Son of man, the house of Israel is become dross to me: all of them are brass and tin and iron and lead, in the midst of the furnace; they are the dross of silver.

As they gather silver and brass and iron and lead and tin into the midst of the furnace, to blow the fire on it, to melt it; so will I gather you in my anger and in my wrath, and I will lay you there, and melt you.

As silver is melted in the midst of the furnace, so you will be melted in its midst; and you will know that I, Yahweh, have poured out my wrath on you.