Such great stones no doubt they carried up with them, whereby they might defend themselves, or offend those who assaulted them. Here the justice of God is remarkable in suiting the punishment to his sin. He slew his brethren upon a stone, Judges 9:5, and he loseth his own life by a stone.
Related Commentaries of Judges 9:53
Judges 9:53
53 And a certain woman cast a piece of a millstone upon Abimelech's head, and all to brake his skull.