Abimelech's act was horrific, but the verse specifies a particularly cruel dimension to his sin. What makes it so egregious?
The verse specifically calls out Abimelech's wickedness 'which he did unto his father, in slaying his seventy brethren.' This phrase points to several layers of evil. First, it was an act against his own father, Gideon (Jerubbaal), by wiping out his lineage. Second, it was fratricide – the murder of his own brothers. This wasn't just a political power play; it was a profound violation of family bonds and human life. The sheer number, seventy brothers, underscores the brutality and completeness of his ambition. Such an act went against the very fabric of human society and the honor due to parents, as emphasized in the Mosaic Law.