The theme of tefilah seems to sneak its way between the lines of the story of the meraglim. Moshe davens for his beloved talmid Yehoshua, which of course begs the question of why he did not daven for anyone else if he smelled danger. Kalev takes a detour to Chevron to daven at the kever of the Avos, and Rashi makes the point that noticably missng are the tefilos of the other meraglim. And yet there is an even larger component of tefilah hidden in the parsha.
The biggest question, the unavoidable question, that one must grapple with in reading the parsha of the meraglim is what was Moshe Rabeinu thinking. Was there any doubt in his mind that Eretz Yisrael was "eretz zavas chalav u'devash?" Surely not. Yet if the purpose of sending spi was purely to discover the best military strategy, why ask them to scout out whether the land is "shmeina hi im razah," whether, "ha'yesh bah eitz im ayin?"
R' Yehoshua of Belz has an interesting insight that brings us back to a gemara discussed in a post way back in 2006 (link1,link2)If you rent a field with payment being a certain number of bushels from your crop, and you agree to grow wheat (for example), if the whole city suffers a flood you owe nothing -- it's like an implicit act of G-d clause (B.M. 106). However, if instead of the agreed upon crop of wheat you plant barley, even if the entire city gets flooded, you still owe the owner payment. Why? What happened to the built-in act of G-d clause? The gemara answers that the difference in tefilah. If the owner and you agree that you will plant wheat, and despite his davening for nothing to go wrong with that wheat crop the field gets flooded, you are off the hook. But if you plant barley, the owner has a right to come back to you and say that he davened for nothing to go wrong with the wheat crop -- had you lived up to the agreement and planted wheat, maybe in fact nothing would have gone wrong! Because you planted barley, his tefilah accomplished nothing and you have to pay.
I ask you -- if the owner of the field knew you were going to pull a switch and plant barely instead of wheat, don't you think he would want the barley to grow so he could collect his due? Don't you think that had he known, just like he davened for wheat thinking you were planting wheat, he also would also have davened for bracha and hatzlacha for barley? In fact, isn't it implicit in the fact that he davened for wheat thinking his sharecropper was planting wheat that he also wants Hashem's bracha for barley if his sharecropper plants barley? Why does he have to spell out the obvious?!
Yet we see a chiddush gadol from this gemara that in fact you do have to spell things out. If you daven for wheat, you stand to gain a bracha on wheat and wheat alone. If you daven for barley, you stand to gain a bracha on barley alone. Words matter. Tefilah is not Hallmark -- it's not just the thought that counts.
The reason why Moshe wanted precise information about Eretz Yisrael, says the Belzer Rebbe, is because Moshe wanted to daven for Bnei Yisrael's success in the conquest of the land. Had Moshe and Bnei Yisrael had a wrong impression, their tefilos mght be completely off base and ineffective. By knowing the nature of the land, they could direct their tefilos like precise missiles. (True, one could be mechaleik between the case of the gemara, where the tefilos were done for the wrong crop, and Bnei Yisrael's situation where they could have still offered general tefilos, but the point remains that tefilah is enhanced by greater specficity.)
Unfortunately it's late and my keyboard is broken, so maybe I'll come back to this post when I have more time and will tie things up. Al regel achas: Were these tefilos a tnai in the battle of conquest being successful, or perhaps the physical battle was just a tnai in these tefilos coming to fruition? I think perhaps Moshe sent the spies with the hope that the latter would be true,while unfortunately the meraglim took the former view. Moshe was aware of the danger of this shift in attitude and therefore he prepared Yehoshua in particular with his tefilos, because it was Yehoshua who already served as general while Moshe stood to the side and davened in the war against Amalek - Yehoshua was the physical arm of the army while Moshe was its spiritual heart.