כֻּלָּם֙ סָרֵ֣י סֽוֹרְרִ֔ים הֹלְכֵ֥י רָכִ֖יל נְחֹ֣שֶׁת וּבַרְזֶ֑ל כֻּלָּ֥ם מַשְׁחִיתִ֖ים הֵֽמָּה׃
그들은 다 심히 패역한 자며 다니며 비방하는 자며 그들은 놋과 철이며 다 사악한 자라
Rashi on Jeremiah
going tale bearing between copper and iron. They introduce hatred between two princes who have the power to provoke one another. That is what I heard. But I say, they are tale bearers, and they are as strong as copper and iron to maintain their falsehood. Jonathan, however, renders this word רכיל as an expression of guile (נוכל). They go with guile as one mixes copper with iron. נוכל is an expression of plot. Comp. (Gen. 37:18) “And they plotted (ויתנכלו) against him to slay him.”