Judges 9:53

A certain woman. Even the women were helping with the defense. While the men would use bows and spears, women could roll down heavy stones on those who exposed themselves by venturing near the base of the tower.

Piece of a millstone. Literally, “millstone of riding”; that is, the upper half of the millstone that was turned while grinding in contrast to the lower stone that remained stationary. The fact that this woman had a millstone suggests that the tower may have been stocked with grain and instruments for grinding flour in anticipation of a siege.

All to brake his skull. An obsolete English phrase over the meaning of which there has been much controversy. The Hebrew says, “crushed his skull.” The word for “skull” here is gulgoleth, from which comes the name Golgotha, the place where Jesus was crucified. Even if Abimelech had been wearing a heavy helmet, such an object falling from a height of 30 or 40 ft. would crush his head.