While I am a great supporter of Aliyah, I realize that in many cases moving to Israel is simply not possible for everyone. However, there is one issue which I would like to clarify. Very often you hear people say that there is not a mitzvah to make Aliyah today. They cite the fact that the Rambam did not include the mitzvah to live in the Land of Israel on his list of Torah commandments as recorded in the Sefer HaMitzvot.
During my years of learning at the Mercaz HaRav Yeshiva in Yerushalayim, our Rosh Yeshiva, HaRav Tzvi Yehuda HaKohen Kook, of blessed memory, would remind students each year that the different lists of Torah precepts which different Sages have composed have no halakhic ramifications . Halakha is drawn from the legal codes which appear in works like the Shulchan Aruch and the Mishna Torah. A Jew seeking to conduct his life according to the commandments of the Torah finds halakhic rulings in these legal sources and not in the different lists.
For example, in contrast to the Rambam, the universally-recognized Torah Giant, the RambaN, does include living in Israel in his list of Torah commandments (Supplement of the Ramban to the Sefer HaMitzvot of the Rambam, Positive Commandment 4). His ruling is cited in the Shulchan Aruch as the definitive law (Even HaEzer, 75:3. See Pitchei Tshuva there, sub-section 6).
The Rambam, in his classic work of halakha, the Mishna Torah, makes the obligation of living in Israel quite clear.
-In the Laws of Kings and Their Wars, he states the prohibition against leaving the Land of Israel to dwell outside of the Land.
-He describes the great love the early Sages had for the Land and quotes the Gemara in Ketubot: “"Always a Jew should live in the Land of Israel, even in a city where the majority of inhabitants are idol worshippers, and not live in the Diaspora, even in a city where the majority of residents are Jews" (Rambam, Laws of Kings, 5:2. Ketubot 110B).
-Also in the Laws of Marriage, the Rambam clearly rules that living in the Land of Israel is a supreme and overriding mitzvah. He rules concerning a husband and wife living in the Diaspora, that if the wife wants to move to Israel and the husband does not, then the Jewish Court forces him to grant her a divorce and give her full divorce payment as set forth in their Ketubah marriage contract. If he wants to go on aliyah to Eretz Yisrael and she does not, then she must agree to a divorce with no Ketubah payment (Rambam, Laws of Marriage, 13:19. Shulchan Aruch, Even HaEzer, 85:3).
-Also, the Rambam emphasizes the centrality of Eretz Yisrael to Torah and Am Yisrael in Sefer HaMitzvot concerning the positive precept of the Sanctification of the new moon which can only be established by the Jews in Israel, irrelevant of their status in Torah scholarship (Positive Commandment 153. Laws of Sanctifying the New Month, 5:3).
The question why the Rambam does not list living in Israel as one of the 613 precepts is more of a philosophical question and not a halakhic one. There are instances where commandments do not appear on this list because they are precepts which encompass all of the Torah, or because they derive from Rabbinic decree, or because they were not practiced at the time of the list. When answering the question regarding living in Israel, HaRav Tzvi Yehuda would clarify the Rambam’s methodology for determining the precepts on the list, as set forth by the Rambam in his introduction:
“The reason the Rambam does not list living in Israel on his list is not because he thinks it is less of a mitzvah – he thinks the opposite! It is more than a mitzvah! In his introduction to his Sefer HaMitzvot the Rambam established fourteen rules by which certain mitzvot are not included in the list, like those of Rabbinic ordinance. Also an encompassing mitzvah which is above the normal value of the precepts is not included in the list (Rule 4). Dwelling in the Land of Israel is an encompassing commandment. Because of this the Ohr HaChaim HaKodosh wrote: ‘For living in the Land of Israel is a mitzvah encompassing all of the Torah’” (Ohr HaChaim on Devarim, 30:20).
In his introduction to the Sefer HaMitzvot, the Rambam states in Rule Four: “Commandments which affect all of the mitzvot of the Torah are not included.” As an example he mentions the command, “You shall be holy,” which he explains as keeping all of the Torah, and therefore he does not list it as a separate command.
So too with the mitzvah to live in Eretz Yisrael. It is an all-encompassing mitzvah, not only because over a third of the mitzvot can only be performed in Israel where a person must live in order to keep them. Living in Eretz Yisrael is more than this.
The Torah, the Jewish People, and the Land of Israel are three dimensions of the unity of Hashem in the world. The greatest sanctification of Hashem can only occur when all of these factors are unified together, as the Prophet declares, “For from Zion will go forth the Torah, and the word of Hashem from Jerusalem.”
Not only did the Rambam believe that living in Israel is a full-fledged commandment – he believed it to be a major foundation of our faith and a pillar of all of the Torah.