Why wasn’t the Torah given in the Land of Israel? Since the Land was given by G‑d to the Jews to be a holy nation in their own Holy Land, wouldn’t it seem to make more sense for them to receive the holy Torah in such a holy place as Israel or Jerusalem?
This is a challenging question, and there are several possible answers.
It is true that Israel is the Holy Land and that the quality of Torah and mitzva observance there is considered higher than anywhere else in the world. The Talmud (Bava Batra 158b) states that even the air of the Land of Israel is conducive to spiritual growth.
However, for this reason G‑d gave the Torah to the Jews before entering the Land in order to prepare them for the elevating experience of entering it, and to ensure that the Land would not be defiled by non-observance upon their arrival. Thus, one reason for giving the Torah in the wilderness was in order to ready the People for the special quality of the Land.
Another reason was to indicate that even though the ultimate place for Torah learning and observance is the Land of Israel, nevertheless, it is not dependent on the Jewish People being in the Land. And even in exile they connect to G‑d through the Torah. In fact, this implies that the importance of the Torah precedes that of the Land. While it’s best for the Jewish People to be committed to Torah in the Land, it’s better to be committed to Torah outside of Israel than to be in Israel with no Torah.
Additional reasons mentioned in the sources as to why G‑d did not give the Torah in Israel but rather in the wilderness include: To teach that just as the wilderness is ownerless and freely accessible to all, so too the Torah is free and open to all (Tanchuma); Just as the wilderness is materially sparse and simple, so too the Torah is found among people who refrain from luxuries and are humble (Nu. Raba 1); And just as the wilderness is traversed by all, so should a Torah scholar be willing to be plied for his wisdom by all (Eruvin 54a).
Another interesting idea is that if the Torah had been given in Israel, the Jewish People might come to think that the teachings of the Torah are just for them; or non-Jews might think that they have no connection to it. So G‑d gave the Torah outside of Israel to indicate that non-Jews may also be inspired by the truths of the Torah. Eventually, it was the Jewish People who received the Land of Israel, from which they are to be a light among the nations, such that “from Zion shall go forth the Torah” (Is. 2:3). But the fact that the Torah was originally given outside of Israel enables its universal message to be heard by all.