Matthew Poole and continuators on Judges 9:36

36 And when Gaal saw the people, he said to Zebul , Behold, there come people down from the top of the mountains. And Zebul said unto him, Thou seest the shadow of the mountains, as if they were men .

Who concealed the anger which he had conceived, v. 30. and pretended compliance with him in this Expedition, that he might draw him forth into the Field where Abimilech might have the opportunity of Fighting with him, and overthrowing him.

For in the Morning, as this was, and in the Evening, the shadows are longest, and move most quickly. He intimates, that he was afraid of shadows.