Zebul outlines a secret plan of action for Abimelech. At first glance, the strategy raises practical questions. Setting an ambush in the open field under the cover of night seems unusual compared to waiting for daylight to engage in direct, face-to-face combat. Furthermore, the plan assumes that Gaal and the people will actually leave the safety of the city walls to enter the field, rather than choosing to stay securely locked inside.
Despite these apparent uncertainties, the advice given to Abimelech is highly intelligent [מלבי״ם]. The strategy directs him to gather his men during the night and prepare a coordinated ambush out in the open terrain [ביאור שטיינזלץ].