We find throughout the Book of Yehoshua that B'nai Yisroel captured Eretz Yisroel with relative ease. Their first conquest was that of Yericho, and because of the miraculous way in which the city fell to them, it was understood that they would not take of the spoils. They, the people, were not the real victors, but rather Hashem was. It is thus perplexing that we find (Yehoshua 15:16) Kalev making the following declaration, "Whoever will conquer D'vir, which was formerly known as Qiryat Sefer, I will give my daughter Achsha as a wife". We are then told that Osneal ben Knaz conquers it and is given Achsha as a wife. Why was this particular section of the land more difficult to conquer? The Book of Yehoshua does not inform us, but the Gemara (Temurah 16a) gives us a significant clue.
The above cited Gemara teaches that when Moshe died, 300 halachos were forgotten by the people. Osneal restored them using his understanding and erudition of the oral law. The text that the Gemara uses to prove that he restored these laws is the verse from Yehoshua that teaches that us that he conquered Qiryat Sefer. What might be the connection between these two subjects?
Harav Dovid Shlomo Eibshitz z"l, the author of the L'vush on Yoreh Deah and Orach Chaim, writes a most fascinating idea in his sefer Arvei Nachal ( Parshas Shelach, Drush 2). The reason that the Jewish nation conquered Eretz Yisroel with relative ease is because the Torah is the blueprint of the world. " Histakel b'Oraysa u'bara alma" - Hashem looked in the Torah and created the world. Eretz Yisroel is inextricably metaphysically bound with the Torah, and indeed the Torah provides the very life and vitality to the land. Each part of Torah maintains a particular piece of land in Eretz Yisroel. Thus it is understandable that their primary preparation for the conquest of the land was not a military academy. Rather their training at Har Sinai, where their acceptance of Torah and their commitment to its perpetuation enabled them to conquer the land. When Moshe died and they forgot 300 Torah laws, they were lacking the spiritual munitions to conquer D'vir. Osneal conquered not only with the sword, but more importantly with the restoration of the sefer, by his Torah, as alluded to in the name Qiryat Sefer.
What is true regarding Osneal is true regarding each and every Jew. The Zohar teaches that the very name Yisroel is an acronym for 600,000 letters of Torah corresponding to 600,000 Jewish souls (" yesh shishim rivo osiyos laTorah"). Each Jew has his own individual portion of Torah. It is for this reason, suggests the Arvei Nachal, that the land of Israel was divided by lottery, under Divine supervision. Not only did this prevent any quarrel and jealousy among the people regarding their particular part, in addition it precisely matched every individuals "portion", his mastery of - and commitment to - Torah, with his parcel of land. Each settler provided unique nourishment to the soil.
The Jew prays (at least thrice daily) regularly, " v'sain chelkainu b'sorasecha" - may we actualize our unique potential in your Torah. Each person, given his intellect, desire, and circumstances, acquires his portion of Torah. In the Shabbos Mussaf we beseech Hashem, return us to Eretz Yisroel, "v'sitoeainu b'gvulainu" - implant us in our "boundary". With the insight of the Arvei Nachal we now have a deeper and more personally relevant understanding of these prayers.
Finally, in Parshas Kedoshim (19:23) we read, "when you shall come to the land and you shall plant any food tree..". The Ohr HaChaim Hakadosh reminds us that often beyond the literal explanation, a much deeper thought is being presented. He reminds us that often the word eitz (tree) refers to a tzadik. In Parhas Shlach when Moshe instructs the meraglim (spies) as to what to note, he asks them (Bamidbar 13:20) "are there trees in it?" Of course Moshe knew three were trees, rather he was asking in keeping with the Talmud ( Bava Basra 15a) "is there among them a righteous man who can protect them through his merit - as a tree protects." R. Yose (Shabbos 118b) refers to his five sons - all of whom were prominent men - as five cedars within the Jewish people. Similarly (Devarim 20:19) "do not destroy its trees" is understood by the Zohar to mean its educated men. Thus, our verse which teaches us the importance of planting trees in Israel is referring not only to the earthly ecology, but also to a higher one as well, namely when you come into the land, educate your children in Torah, as the land itself yearns for its Torah, and assist the student to acquire more of it.