The Torah commands us, "The land shall not be sold forever, because the land belongs to Me; for you are sojourners and residents with Me" (Vayikra 25, 23). The Seforno explains that although the pasuk in Tehillim states "The heavens are the heavens for Hashem and the land He gave to mankind," nevertheless, Eretz Yisrael is not included in that declaration. The land still belongs to Hashem, and we are mere sojourners in His land.
Rav Wolbe (Alei Shur vol. I pg. 282) comments that accordingly our entire inheritance is merely a kinyan peiros -the ability to eat the fruits of the land, while the ground itself remains in the possession of Hashem. This idea is emphasized in the words of the bracha achrona. We thank Hashem, "For the desirable, good and spacious land that You were pleased to give our forefathers as an inheritance, to eat from its fruit and to be satisfied from its goodness." Our ownership of the land is limited to eating its produce.
The truth is that the ability to eat the produce of the Eretz Yisrael is a gift much greater than the superficial ingestion of food. In the bracha achrona we ask Hashem to return us to Eretz Yisrael "And we will eat its fruit and be satisfied by its goodness." Some poskim (see Tur O. C. Siman 208) maintain that these words should not be mentioned because the reasons that we desire to return to the Promised Land is not for material benefits i.e. to partake of its produce. Rather, we yearn to return to enable us to perform the mitzvos that can only be performed in Eretz Yisrael.
However, the Bach (ibid.) asserts that the words should be mentioned, and he bases his opinion on a pasuk in this week's parsha: "Do not defile the land in which you dwell, in whose midst I reside, for I am Hashem Who resides in Bnei Yisrael" (Bamidbar 35, 34). He explains that when Bnei Yisrael refrain from aveiros, Hashem literally resides inside the Land. Hence when they ate the fruit of the land they were, so to speak, ingesting the Shechina! Accordingly, the Shechina resided inside of Bnei Yisrael! Should the land become contaminated with sin, the Shechina that resided in the Land will depart. Moreover, when the fruit which draws its nutrients from this impure land is eaten, the impurity will then be transferred into the one eating the fruit, thereby ejecting the Shechina from his body too! Hence, when we make a bracha achrona we are expressing our spiritual desire to once again merit to eat from the fruits of the land that are imbued with the Shechina, thereby transforming our physical bodies into an abode for the Shechina! Indeed, acquiring "merely" the produce of the land is no small achievement! It is the conduit for hashra'as ha'Shechina; the very reason we were given the land.
With this, says Rav Wolbe, we can understand an interesting Gemara. Chazal ask (Sotah 14a) why Moshe Rabbeinu had such a great desire to enter Eretz Yisrael. "Was he interested in eating its fruit or becoming satisfied from its goodness? Rather, he wanted to perform the mitzvos that are connected to the land and can only be performed there." Chazal specifically focused on the eating the fruits and goodness of the land because, as mentioned, they are a means of connecting to Hashem. Chazal were wondering; could it be that Moshe needed the fruits to connect to Hashem? Even without ingesting the fruit Moshe had achieved the level where he had turned his body into an abode for the Shechina!
During the Three Weeks we mourn the destruction of the Bais Hamikdosh and our galus from Eretz Yisrael. This idea gives us an added appreciation for just what we are missing. Hopefully it will also give us an added impetus for a heartfelt prayer for the much needed Geulah Shleimah bimheirah b'yameinu!