John Gill's Exposition of the Whole Bible
Ezekiel 22:18
Son of man, the house of Israel is to me become dross,.... Vile, despicable, useless, and unprofitable; to which the wicked of the earth are compared, Psalms 119:119 and here the Lord's professing people, they differing nothing from them, being sadly degenerated; formerly they were as silver, and so they might be reckoned among themselves; but to God, who is omniscient, the searcher of the hearts and reins, who saw all their actions, and knew the spring of them, in his sight they were as dross:
all they are brass, and tin, and iron, and lead, in the midst of the furnace: or "crucible" f; where they are put together, in order to be set in the furnace, and melted down. It is not usual to put so many different metals together for melting, but separately; but here it seems to intend a mixture of them all together; and so the Targum and Septuagint render it,
"all they as brass, c. are mixed''
several metals of the baser sort are here mentioned, by a gradation from the better to the worse; tin being not so good as brass, and iron of less value than either, and lead than any of them. Some think the different characters of the people are here described; impudent persons by "brass"; hypocrites by "tin"; cruel and savage ones by "iron"; and such as were sottish and stupid by "lead"; or, as others, covetous ones:
they are even the dross of silver; once they were like silver, precious and valuable, while they retained the true religion, and the worship of God, and behaved agreeably to their character in the performance of all good works, and were in outward flourishing circumstances; but now degenerated from the pure worship of God, and sunk into idolatry and wickedness, and become poor and miserable.
f כור "catinus", Junius and Tremellius, Polanus, Grotius, Cocceius, Starckius.