1)
Verse 7 already told the shepherds to hear Devar Hashem? Why is this repeated?
1.
Radak #1: The matter is repeated to strengthen it.
2.
Radak #2: Here, Targum Yonasan adds 'evil [leaders], return to the Torah and I will have mercy on you. Listen to Torah's teaching and accept Hashem's word.'
3.
Malbim: Because you cannot claim that you departed from being shepherds, rather, you are the shepherds, hear Hashem's decree against you.