"K'Chagavim V'Chen Hayeenu B'Enayhem" (Perek Yud Gimmel Pasuk Lamed Gimmel).When the Meraglim returned from Eretz Yisrael, they reported to Moshe and the rest of Klal Yisrael on what they saw. As we know 10 out of the 12 had nothing good to say about the land. They said that they were as grasshoppers in the eyes of the residence of the land.

The Baal HaTurim brings down a Medrash that says that they saw a giant eating a remon, pomegranate, and then throwing away the shell. The Meraglim were able to crawl inside the shell and use it as protection from the shade.

The Gemara in Chagiga <>(Daf Tes Vov Amud Bais) relates that one of the beautiful things about Rav Meir was "remon matza", he found a pomegranate, "tocho achal", he ate the inside, "v'kleepaso zarak", and threw away the peel. What does this mean? It means that Rav Meir never concentrated on the simple outside of anything, he always concentrated on the deeper meaning of things. (Both the Divrei Yisrael pg. 134 and the Imrei Shaul Daf Kof Ayin Ches Siman Yud Tes go into this subject in more detail)

This is just the opposite of the Meraglim. They sat in the shell - their concentration was on the appearance of Eretz Yisrael and that is why they were nechsal - that is why they sinned.