What is the meaning of "Mi Avimelech u'Mi Shechem Ki Na'avdenu"?
Rashi: Who is Avimelech that he should rule over Shechem, and who is Shechem to be slaves of Avimelech?
Malbim: What is Avimelech's connection to Shechem, that we should serve him? His father was Yeruba'al, who was not from Shechem; lineage is primarily from the father!
What is the meaning of "ha'Lo Ven Yeruba'al u'Zvul Pekido Ivdu Es Anshei Chamor..."?
Rashi: Do you serve him because he is Yeruba'al's son? He has no authority, nor his appointee Zevul. If you want to pick a master, serve Anshei Chamor - he was Nesi ha'Aretz!
Mahari Kara: Anshei Chamor died many years ago [via Shimon and Levi]. Just like there is no benefit through serving them, there is no benefit through serving Avimelech. He cannot save you!
Radak: Avimelech and Shechem (ben Chamor), who was mayor earlier, are the same. Even though now Avimelech is king, also Shechem used to be king of this city! If so, serve the men of Chamor, Shechem's father!
Malbim #1: You are foolish like Chamorim (donkeys), the most feeble minded animal. Ga'al called Avimelech 'Chamor', who used to be Nasi here.
Malbim #2: Ga'al called Avimelech 'Shechem', to disgrace him. He wants to merit to rule because he is the son of Nesi ha'Aretz, just like Shechem ben Chamor in earlier days. Who is Avimelech and who is Shechem Nesi ha'Aretz, that we should serve him?! He is not Vadai Ben Yeruba'al, for he is a concubine's son; concubines are often Mezanah. His mother was Mezanah with Zevul, Yeruba'al's appointee. Perhaps Avimelech is Ben Zevul! If you want to serve him because his father was Nesi ha'Aretz, serve Anshei Chamor Avi Shechem - they were Nesi'im beforehand!
What is the meaning of "u'Madu'a Na'avdenu Anachnu"?
Malbim: I and my brothers, we were not born in Shechem. If you want to serve Avimelech, we need not.