Commentary for Proverbs 10:20

The tongue of the righteous is choice silver for he knows how to reprove.

the heart of the wicked is worth little for he does not heed the reproof of the righteous man. Midrash Rabbi Tanhuma (Ki Thissa 6) states: This was stated concerning Iddo the prophet, who called [in prophecy] about the altar in Beth-El, and Jeroboam, although his hand had become stiff, did not heed the reproof, as it is said (I Kings 13:6): “Entreat now the Lord your God, etc.”; but not “my God, etc”; (ad loc.): “and the king’s hand was drawn back to him, and it was as before.” Just as before, he was standing and burning sacrifices to idols, so was it at the end.