The following was first published in Parsha Pearls, Chayei Sarah 2001 (year not on the original) by yours truly and is presented here in its entirety for Yom Ha'atzma'ut, and also for Parshas Kedoshim.
In this week's Parsha, we learn all that Avraham did in order to procure a burial plot for his wife, Sarah. Why did the Torah deem it necessary for us to know all these facts?
The ibn Ezra explains (23:18) that the Torah wished to show us two things. One, the importance of Eretz Yisrael for both the living and the dead, and two, the fulfillment of Hashem's promise to Avraham that Eretz Yisrael will belong to him and his descendants.
The Ramban (23:19) askes on the explanations of the ibn Ezra: How does this epsode illustrate the uniqueness of Eretz Yisrael for the living and the dead, just because Sarah died in Eretz Yisrael, and was buried there and not elsewhere. (If, however, she had died outside of Eretz Yisrael and was brought there for burial, this would illustrate the uniqueness of Eretz Yisrael.) Furthermore, the Ramban asks, Hashem's promise was to give the entire Eretz Yisrael to the descendents of Avraham, and this episode only refers to one small field. How do we see a fulfillment of Hashem's promise to Avraham?
The Ramban therefore writes that the Torah showed us this episode for two other reasons. One, to show us that Avraham was well respected by the Bnei Cheis, a fulfillment of the divine promise of "va'agadlah shimecha - And I will make your name great." (See Perek 12, Passuk 2.) Two, to record for us the location of the graves of our forefatehrs so that we can honor those places.
My rebbie, Harav Moshe Soloveichik, Shlit"a, suggested an answer to the questions of the Ramban on the ibn Ezra. Reb Moshe said that Avraham insisted on buying the fields from Efron, while he could have acquired it from him for free. This was to show that Eretz Yisrael is our land. The definition of Eretz Yisrael, as explained by Reb Yoshe Ber, and the roshe HaYeshiva, zt"l, is that which belongs to every Jew, not as shutfus (partnership). Avraham's purchasing the field from Efron made the field belong to the Jewish people. This answers the second question of the Ramban, because now that the land belongs to every Jew, there is a fulfillment of Hashem's promise. The answer to the first question of the Ramban can be seen by the differences that exist between the purchases of different pieces of property. When one buys a regular piece of property, like a house, he may eventually sell it. The purchase of a grave, however, is eternal. To illustrate this point, Reb Moshe gave the example of Har hazeisim: the fact that there is a cemetery prevents its being given away. In this way one can still be a supporter of Eretz Yisrael, even upon death.
I would like to add that the explanations of the ibn Ezra and Ramban are influenced by the way they define the uniqueness of Eretz Yisrael. The Ramban in Sefer Vayikra, Perek 18, Passuk 25, in addressing why Eretz Yisrael will eject sinners, explains that when Hashem created everything, He established a star or sign for each place. However, He created no such sign for Eretz Yisrael. Hashem Himself is the sign for Eretz Yisrael, and as such it is a holy place that cannot tolerate sinners. The Ramban says therefore that the kedusha of Eretz Yisrael is due to an external force [i.e., Hashem as the sign -ed.] , and as such he cannot learn the uniqueness of Eretz Yisrael from this episode. This is because he feels it was special for a different reason, not contained in this episode. The ibn Ezra, on the other hand, holds that Eretz Yisrael is special due to maasim (deeds) we do, and therefore we can learn the uniqueness of Eretz Yisrael from this Parsha, for it displays the great maasim of Avraham.