Judges 9:6 - Matthew Poole's English Annotations on the Holy Bible

Of Millo; of a place or person so called; some eminent and potent family living in Shechem, or near to it; either the family of Abimelech's mother, or some other: or, and all Beth-millo; so Beth is not a house, but a part of the name of the place. Made Abimelech king, to wit, over all Israel, Judges 9:22, which was a strange presumption for the inhabitants of one city to undertake; but they had many advantages and encouragements for it; as the eager, and general, and constant inclination of the Israelites to kingly government; Abimelech's being the son of Gideon, to whom and to his sons they offered the kingdom, Judges 8:22; and though the father could and did refuse it for himself, yet they might imagine that he could not give away his son's right, conveyed to them by the Israelites, in their offer; the universal defection of the Israelites from God to Baal, whose great patron and champion Abimelech pretended to be; the power and prevalency of the tribe of Ephraim, in which Shechem was, Joshua 20:7, whose proud and imperious spirit, manifested Judges 8:1, Judges 12:1, would make them readily close with a king of their own brethren; and Abimelech's getting the start of all others, having the crown actually put upon his head, and an army already raised to maintain his tyranny. By the plain of the pillar, or, by the oak of the pillar, i.e. by the oak, where Joshua erected a pillar as a witness of the covenant renewed between God and Israel, Joshua 24:26. This place they chose, to signify that they still owned God, and their covenant with him; and did not worship Baal in opposition to God, but in conjunction with him, or in subordination to him.