1)
Why did he say "Shim'u Na"?
1.
Radak: He returns to rebuke their leaders and officers, like he said above (1).
2.
Malbim: Above (1), he justified that all Hashem's ways are Din and Mishpat. Here he concludes ? you despise Mishpat, and make crooked everything that intellect obligates, to go against straightness and intellect, to the point that you do not heed etiquette that people agreed upon, and not straight intellect.
2)
How do they make the straight crooked?
1.
Radak: They make the straight path crooked. All their ways and deeds are theft.
