Albert Barnes Commentary Ezekiel 22:17-22

"And the word of Jehovah came unto me, saying, 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. Therefore thus saith the Lord Jehovah: Because ye are all become dross, therefore, behold, I will gather you into the midst of Jerusalem. 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. Yea, I will gather you, and blow upon you with the fire of my wrath, and ye shall be melted in the midst thereof. 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." — Ezekiel 22:17-22 (ASV)

The fifth word of judgment. The furnace. In the besieged city the people will be tried and purged (Ezekiel 22:18).

Dross — A frequent metaphor that denotes not only the corruption of the people, who have become like base metal, but also a future purification by which, the “dross” being burned away, the remnant of good may appear.