What does Judges 9:34 mean?

Abimelech is away from the city over which he rules (Judges 9:1–6). Zebul, his governor, has become aware of a threat. A man named Gaal and his relatives are stirring up an open rebellion against Abimelech's rule. Gaal has even bragged that he would remove Abimelech from office by force (Judges 9:26–29).

Furious, Zebul sent a messenger to Abimelech with a strategic plan. Abimelech acted on this wise strategy (Judges 9:30–33). Under cover of darkness, he and his men hid in the hills surrounding the field outside the city's eastern gate. If they attack at dawn, they will be hidden in shadow until they reach the field. Even then, with the sun at their backs, the city's defenders will be blinded by the rising sun. Abimelech's men are also divided into four different companies, so they can attack the gate from four different positions.