'Furnace' in the Bible

Son of man, the house of Israel is become dross unto 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 upon it, to melt it; so will I gather you in mine 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 shall ye be melted in the midst thereof; and ye shall know that I, Jehovah, have poured out my wrath upon you.