Jeremiah 6:28 Midrash

כֻּלָּם֙ סָרֵ֣י סֽוֹרְרִ֔ים הֹלְכֵ֥י רָכִ֖יל נְחֹ֣שֶׁת וּבַרְזֶ֑ל כֻּלָּ֥ם מַשְׁחִיתִ֖ים הֵֽמָּה׃

They are all grievous revolters, Going about with slanders; They are brass and iron; They all of them deal corruptly.

Read midrashic interpretation of Jeremiah 6:28: and classical rabbinic exegesis.