What does Judges 9:2 mean?
Abimelech (Judges 8:29–31) wants to be king of Shechem and maybe all of Israel. His father Gideon refused to be named the official ruler of the nation (Judges 8:22–23). And yet, it seems he became the unofficial king of Israel. One translation for Abimelech's name is "the king is my father." This name might have been chosen by the boy's mother, a concubine who lived in Shechem. Abimelech is ambitious to take his father's place, whether or not the crown is official, in any way he can.To take over immediately means drastic action, so Abimelech's plan requires violence. Gideon fathered seventy sons. Abimelech was certainly not the oldest of them. Nor was he likely a full-blooded Israelite. To have undisputed possession of a throne, even the throne of the city of Shechem, he would have to eliminate the rest of Gideon's sons. To rule, Abimelech is willing to murder his own brothers. He wants the rulers of Shechem to give him both permission and assistance, and to name him king once the deed is done.
Abimelech recruited his Shechemite mother and her extended family. They petition the leaders of the city on his behalf. He reminds his relatives that he is one of them; they should be loyal to him. Further, they ought to prefer having a single, local leader instead of serving a large group of distant people: "Is it better to be ruled by the seventy sons of Jerubbaal or just one?"
The name Jerubbaal comes from Gideon's early experiences in fighting Canaanite idolatry (Judges 6:32). This may have come to be thought of as his Canaanite name, with Gideon as his Jewish name.