He went to his father's house at Ophrah, and killed his brothers the sons of Jerubbaal, being seventy persons, on one stone: but Jotham the youngest son of Jerubbaal was left; for he hid himself.
Abimelech was able to secure some popular and financial support by politicking. He hired some assistants who promoted him and probably helped him assemble and assassinate 69 of his 70 brothers (Judges 9:5). He executed this slaughter on "one stone" (Judges 9:5) suggesting a well-planned mass murder. Compare and contrast the similar story of Jehu’s slaughter of Ahab’s sons in 2 Kings 10. Note how departure from God, idolatry, and self-assertion result in hatred and violence. [Note: See McCann, who traced the twin themes of idolatry and self-assertion, violations of the Ten Commandments that require submission to the sole sovereignty of Yahweh in one’s person and works, through the Book of Judges in his commentary.] 