שופטים, פרק ט׳, פסוק ל״ג

A military advisor often recognizes that a direct assault is less effective than a well-timed surprise. Zebul advises Abimelech to abandon the idea of a frontal war against the people of Shechem and instead rely on a calculated ambush [ביאור שטיינזלץ]. The strategy requires Abimelech to rise early in the morning and launch a sudden attack. As part of this maneuver, he is told to spread his forces out across the terrain, adopting a standard combat formation [מצודת ציון].

The success of this trap depends entirely on drawing the enemy out into the open. Zebul anticipates that Gaal and his men will leave the safety of the city to confront the attackers [ביאור שטיינזלץ]. By stepping out to fight, Gaal will essentially be forced to make good on the boastful claims he had proudly declared earlier [מצודת דוד]. However, this move is a fatal tactical error; abandoning the city leaves it completely exposed, giving Abimelech the perfect opportunity to conquer it without difficulty [מלבי״ם].

Once the enemy is out in the field, Abimelech is instructed to strike with his full power [מצודת דוד, ביאור שטיינזלץ]. He is given the freedom to handle Gaal however he sees fit, whether that results in killing him on the spot or taking him as a live prisoner [מצודת דוד]. To execute this final blow effectively, the plan calls for a division of troops. One group will position themselves at the city gates, cutting off any chance for Gaal and his men to retreat to safety, while the remaining forces engage them directly in open combat [מלבי״ם].