Or HaChaim on Numbers 13:33/אור החיים על במדבר י״ג:ל״ג

1 ונהי בעינינו כחגבים, "we felt in our own estimation as if we were grasshoppers (by comparison to them), and so we appeared in their eyes." The spies revealed by this comment that they felt vastly inferior even to the people in that land that did not fit the description of being men of stature. They knew this when comparing their own physiques to that of the average person whom they had observed.