I
The disaster of the spying mission to the Land of Israel had millennia-long consequences (see Sanhedrin 104b ). The spies succeeded in convincing the Jewish people to deny G-d's Omnipotence (Shlach 13:31 and Rashi) and to be ungrateful for the enormous gift of the beautiful Land of Israel (13:32). This led to a decree of death for the entire generation leaving Egypt.
How surprising it is, then, that Yehoshua, one of two spies who did not sin along with the others, sends two spies again to scout out Eretz Yisrael before crossing over the Jordan river as recorded in our Haftara! Ralbag explains that Yehoshua's purpose was merely to strengthen the nation's resolve by proving to them that the Canaanites were frightened of the Jews' imminent entry. This was similar to the episode where Gidon was instructed by Hashem to listen to the dream of the Midianite soldiers indicating their imminent defeat (Shoftim 7:11 ff.). This approach is verified by the fact that this seems to be the only message relayed by the spies to Yehoshua (Yehoshua 2:24).
Malbim (on Yehoshua) presents another interpretation based on an approach he developed in our parasha. Distinguishing between a tar - as the spies are described in Sh'lach - and a m'rageil - as the spies are depicted in Yehoshua, Malbim writes that the purpose of a tar is to determine whether the land being investigated is worthwhile to conquer and settle. The purpose of a m'rageil, by contrast, is to seek out military weakness in the enemy and exploit it to the benefit of the invading army. (Compare Yosef's accusation against his brothers that they are m'raglim (Mikeitz 42:9).) The latter is only necessary if the land is to be conquered by conventional, natural means. If G-d would bring about the conquest miraculously, this method would be superfluous. Consequently, Hashem only gave permission for Moshe to send tarim to verify for them the physical and spiritual beauty of the land to assuage their fears. The spies, instead, utilized their mission to slander the Land bringing about the tragic conclusion of their mission. (Rav Soloveitchik, in his essay, "The Singularity of the Land of Israel," published in Reflections of the Rav (1979), presents a similar approach. This approach contrasts with Ramban who maintains that the sending of the spies was intended to be a military mission.)
Yehoshua, on the other hand sent m'raglim (2:1) to ascertain an appropriate military plan for conquering Yericho. This would not lead to a repeat of sin of the spies of Moshe's generation since it was already accepted by the Jewish nation that the Land was an enormous Divine gift and that it would be conquered by Divine assistance. Yehoshua was determining how to conquer, not if to conquer. (See Malbim for other differences between the two episodes fitting into this basic theme.)
These two different approaches are reminiscent of the different attitudes of the rest of the nations of the world and Am Yisrael concerning the Torah. The nations said "nishma v'na'ase". Let us first determine if we should accept the Torah. K'lal Yisrael proclaimed "na'ase v'nishma". Let us first commit to the Torah; then we will determine how to keep its laws.
Elsewhere (K'riat Sh'ma and the Festivals of Tishrei), we elaborated on the centrality of kabbalas 'ol malchus shamayim and kabbalas 'ol mitzvos and how the three sections of k'rias sh'ma indicate the daily necessity of first reaffirming our commitment to G-d and His Torah, and only then do we mention the actual performance of mitzvos. This, according to Abudarham, is the purpose of a birchas hamitzva - to first accept Hashem's sovereignty and Torah and then to perform the mitzvah in that context.
II
However, Yericho was conquered miraculously. The walls inexplicably sank into the ground after seven circuits were made by the kohanim and the Aron HaKodesh. Why, then, was it necessary for Yehoshua to send spies altogether to see how to conquer the city?
Malbim explains that the angel sent to Yehoshua informed him that the city would be conquered miraculously and not through hidden Divine assistance. Apparently, Yehoshua was under the mistaken impression that the Land of Israel would be conquered through natural means.
These two aspects of Divine Providence - the overtly miraculous and the more hidden Divine assistance - appear constantly in Malbim's writings on Tanach. Based on this duality, he explains the Divine anger at the nation's request for a king (M'lachim 8). A king represented the transition into the more distant mode of hidden providence. During the generation of Moshe in the midbar, and, to some extent, the generation of Yehoshua, Hashem operated with open miracles. This era was a time of more intense connection of the Jewish people to Hashem leading to greater knowledge of Hashem and His Torah and more widespread prophecy. But it also had an additional consequence - more immediate Divine punishment for sins. Klal Yisrael, by asking for a king, was "opting out" of the more intense connection to G-d to be "more normal" like other nations. This, of course, led to Divine anger.
It was known apparently by the leaders of the nation that there would be a gradual transition from one form of Providence to the other one. The exact time of that transition was apparently unknown. The Jewish people would not always remain on the level to merit miraculous Providence. Yehoshua, according to Malbim, apparently thought that the era of the more hidden form of Divine Providence had already arrived after the death of Moshe Rabbeinu. Hashem informed him that this was not yet to be. Rav Rivlin, mashgiach of Yeshivat Kerem B'Yavneh, explained that there was a gradual transition from the overtly miraculous conquering of Yericho to the relatively "natural" battle against the Ai followed by miraculous hailstones only at the end of the battle to battles without any overt miracles but immediate flight of the enemy.
These two modes of Divine Providence are briefly alluded to in the Hallel where we recite "ana Hashem hoshia na, ana Hashem hatzlicha na" - "Please Hashem save us, please Hashem give us success." Sometimes we merit open salvation where there is nothing we can do on our own - "Save us!" Sometimes we only merit Hashem assisting us and blessing our efforts with success - "Give us success!"
Every day, at the end of Shemone 'Esrei, we pray from Hashem to bless us with his "'or panim", the light of his countenance. It was through this that he gave us so many blessings. Perhaps this is a reference to the miraculous Divine Providence. A major current aspect of our Divine service is to recognize the Divine hand even when this second mode is in operation. We all long for the day when Hashem will return His intense Light to Klal Yisrael and will once again perform open miracles for His beloved nation.