Magical wisdom and the magical land (Shlach)

Throughout the Harry Potter books we see magical incantations, potions, and other tricks that Hogwarts students try to use to become smarter, especially when they have tests. In Harry Potter and the Order of the Phoenix (chap 31), as the students prepare for their OWL exams, they're told:

"Now, I must warn you that the most stringent anti-cheating charms have been
applied to your examination papers. Auto-answer quills (pens) are banned
from the examination hall, as are remembralls, detachable cribbing cuffs, and
self-correcting ink."

We will see that the Torah and Talmud also discuss magical wisdom, but of a very different sort than the methods used for cheating at Hogwarts.

This week's Torah portion, Shlach, discusses the story of the spies spying out the Land of Israel.

In a nutshell, twelve spies are chosen to spy on the Canaanite inhabitants of the Land of Israel and report back on what they see. But ten of the spies spoke badly of the Land and disparaged the possibility of the Jews taking control of the Land. Two of the spies, Caleb and Joshua (in Hebrew "Calev" and "Yehoshua") defended the Land and defended G-d's ability to bring the Jews there, but the Jewish people panicked because of the spies report. G-d got angry at them for not believing in the Land's greatness and for not trusting in His ability to bring the Jews into the Land, and as a result they were punished with forty years of wandering.

If we look closely at the verses of the story, we see a strange detail that the Torah seems to emphasize. After the bad report and the people's panic, the Torah says (Num 14:5-6) as follows:

"Moses and Aaron fell on their faces (bowing in prayer) in front of all the people. Caleb and Joshua, among those who were in the Land (of Israel), tore their clothes (in grief)."

If we think about it, there seem to be two very different reactions going on. Moses and Aaron, the spiritual leaders of the people, G-d's chosen prophet and high priest, prayed to G-d not to punish the people. Caleb and Joshua, however, reacted less hopefully, and reacted instead to the grief they felt.

If the spiritual leaders started praying to G-d not to punish the people, why didn't Caleb and Joshua join in? Why were they seemingly pessimistic while Moses and Aaron were seemingly hoping that their prayer would result in things being OK?

Moreover, it seems in fact that Caleb and Joshua were right. Rather than simply forgiving the Jews, G-d's reaction was a pretty harsh punishment. Could Caleb and Joshua have known that the punishment was coming, and been in grief over it, while Moses and Aaron, the prophet and priest, still had hope that ended up being unrealized?

The Chassidic Rebbe from Boston teaches that this is an example of the Talmudic axim that "the air of the Land of Israel makes one wise" (BB 158b). As spiritual and close to G-d as Moses and Aaron were, they had not set food in the Land of Israel, which Caleb and Joshua had. This gave Caleb and Joshua an added wisdom that even Moses and Aaron didn't have, enabling them to understand that G-d was not going to simply forgive the Jews this time, and that a bigger punishment was on the way. This led to their grieving rather than praying optimistically.

This answers a question about the concept of "the air of the Land of Israel makes one wise." Does the air make a person wise only when that person is in Israel, or does it give an added element of wisdom that lasts with the person after leaving Israel? The Bostoner Rebbe concludes from his understanding of the story above that this special Divine wisdom stays with people even after they leave Israel.

It seems to me that an additional condition might be needed, that the wisdom from the Land will only stay with people that want to keep the Land's wisdom with them when they leave. Otherwise, wouldn't the ten other spies who started all the problems also have had Divine wisdom that would have prevented them from the entire sin? It seems necessary to appreciate the Land and the wisdom it imparts for the wisdom to stay with a person who leaves, which would be the only explanation (I think) for why Caleb and Joshua kept this Divine wisdom while the other ten spies obviously didn't.

We see from this a Jewish perspective on earning Divine wisdom. Coming to the Land of Israel is one part, since the Land is G-d's chosen Land with Divinely magical properties such as making people wise. But we also need to appreciate G-d's Land, and G-d's gifts to us in general, to keep the magical wisdom that He gives us.