The beginning of Parshas Re'eh is quite puzzling, for the parshah commences with the mitzvah to pronounce the Berachos and Kelalos on Har Gerizim on Har Eival upon passing over the Yarden, but the text and procedure for this mitzvah are not presented until Parshas Ki Savo. Why, thus, does this mitzvah appear at the beginning of Parshas Re'eh in incomplete form?

Parshas Re'eh is the first in a set of three parshiyos in Sefer Devarim which contain the bulk of the sefer's mitzvos. Parshas Re'eh features ritual mitzvos, Parshas Shoftim addresses the mitzvos of government, its functionaries and public figures, and Parshas Ki Seitzei is devoted to civil laws.

These three parshiyos present many mitzvos that did not heretofore appear in the Torah, as well as a sampling of mitzvos that were already taught. Given that Sefer Devarim was Mishneh Torah (a review of the Torah) for the new generation – a generation that did not undergo the entire Midbar experience - what determined the selection of the mitzvos featured in Sefer Devarim? Why are some of the mitzvos of Sefer Devarim new, while others were initially instructed long ago? Is there any common denominator to the mitzvos of Sefer Devarim?

In Mishneh Torah, Moshe Rabbeinu sought to recreate the full experience of the Midbar as best as possible for the new generation and to teach the new generation the lessons that were presented to the older generation at the beginning of its travels in the Midbar. As such, Moshe reviewed Mattan Torah with the Aseres Ha-Dibros and taught the Shema; he uttered lengthy and eloquent exhortations about the importance of learning Torah and observing mitzvos; he reviewed the several episodes of national sin that occurred in the Midbar, and their punishments and long-term ramifications; and he prepared the nation for battle and entry to Eretz Yisroel, seeking to fortify the people against all challenges in the new Land.

In this vein must we view the mitzvos of Sefer Devarim, for their common themes are (1) review of the basics of Torah as commanded to and experienced by the older generation, and (2) preparation of the new generation for conquest of Eretz Yisroel and life therein. Since the goal of Mishneh Torah was to restate Torah as it related to those who would conquer the Land, the presentation of its mitzvos was uniquely geared to that end.

One special quality of Torah observance in Eretz Yisroel is that of Arvus - communal responsibility for mitzvah performance. Once B’nei Yisroel entered the Land and heard the Berachos and Kelalos at Har Gerizim and Har Eival, which speak to the obligation of each citizen to observe the Torah in his private life, they became obligated to assure that each citizen observed the Torah in his public life as well. (Rashi on Devarim 29:28, from Gemara Sanhedrin 43b) This is the special concept of Arvus that became part of Torah life upon entry to the Land, at the point of the pronouncement of the Berachos and Kelalos at Har Gerizim and Har Eival.   

This answers our original question. The reason that Parshas Re'eh begins with a reference to the Berachos and Kelalos at Har Gerizim and Har Eival is to provide an introduction to the future character of the observance of the mitzvos that are about to be presented. Unlike those mitzvos which were taught to the older generation, the mitzvos which would be observed by the new generation, upon entry to Eretz Yisroel, would bear the quality of Arvus. Thus, the Torah invokes the pronouncement of the Berachos and Kelalos on Har Gerizim and Har Eival in order to present the mitzvos about to be taught in the context of Arvus, in line with the overall function of Mishneh Torah of restating Torah as it would apply to the new generation for Torah life in Eretz Yisroel.

We, too, must take responsibility for communal Torah life to the extent that we are able, following the Torah's mandate to fortify the public's Torah observance and be responsible for the spiritual welfare of all members of the community.