The Torah portion Nitzavim is always read prior to Rosh HaShanah.1 When the portion Vayeilech is separated from Nitzavim and read separately, Nitzavim is then read on the Shabbos before Yom Kippur. This indicates that the portion Vayeilech is related to Yom Kippur. What is the relationship?

Rosh HaShanah and Yom Kippur share a common theme: G‑d is roused with a desire to choose the Jewish people as His subjects. The Jews are thus inscribed and sealed for a new year filled with all manner of revealed and palpable good.

Rosh HaShanah and Yom Kippur differ, however, in that only the inscription for the new year occurs on Rosh HaShanah, while the actual sealing — the culmination of the process begun on Rosh HaShanah — takes places on Yom Kippur.2

The Alter Rebbe explains the connection of Nitzavim to Rosh HaShanahin this way:3 Rosh HaShanah is when G‑d extends His kingship and dominion over the Jewish people.4 This is accomplished when Jews unite so that they are all as one.5

This concept of Jewish unity is also at the heart of the opening statement of Nitzavim: “Today you are all standing before G‑d your L‑rd — your leaders, your tribal chiefs... your woodcutters and water drawers.”6 The verse tells us that, notwithstanding the different levels of individual Jews, all equally stand united before G‑d.

This aspect of Jewish unity is also the focal point of Vayeilech. The portion begins by saying that “Moshe went and spoke the following words to all Israel,”7 i.e., he spoke to all Jews in an identical fashion. The portion concludes with Moshe addressing “the entire assembly of Israel”8 — all of them together in a united manner.

Moreover, the commandments taught in Vayeilechhakhel and the writing of a Sefer Torah — are mitzvos that stress the unity of the Jewish people.

Hakhel,” the commandment to “Gather together the people,”9 equally encompasses all Jews — “men, women, children and proselytes.”10 Indeed, that is why this commandment is termed hakhel, which means “congregation.” In this case, those who congregate lose their individual identity and form an entirely new entity and entirety.

Writing a Sefer Torah, too, stresses the concept of unity, for while Jews differ greatly in their comprehension of Torah, all are equal with regard to the commandment of writing a Sefer Torah.

Although the theme of both Nitzavim and Vayeilech is Jewish unity, there is a difference between these two Torah readings with regard to the manner of this unity:

As mentioned earlier, Rosh HaShanah and Yom Kippur share a common feature, namely, the arousal within G‑d of a desire to choose the Jewish people as His subjects. This theme begins on Rosh HaShanah, continues throughout the Ten Days of Repentance, and culminates on Yom Kippur.

The difference between Rosh HaShanah and Yom Kippur in this regard will help us understand the differences in the manner of unity of the Jewish people as expressed alternately in Nitzavim and in Vayeilech.

Rosh HaShanah, the time when Jews crown G‑d as their King, accomplishes Divine Kingship at its supernal source, while Yom Kippur completes the process by drawing down this aspect so that it will be revealed in this world. Since all this is accomplished through Jewish unity, it follows that these two different aspects also manifest themselves with regard to the manner of Jewish unity itself.

The thrust of Jewish unity on Rosh HaShanah is mainly that of Jews united above — in their source and root; while Yom Kippur expresses this unity here below. As a result, Jewish unity is expressed on Yom Kippur physically as well as spiritually.

Consider: There is no difference among Jews with regard to their observance of the “five afflictions” on Yom Kippur — the prohibition against eating, drinking, etc. Differences may exist between the performance of a good deed by a righteous person and the performance of the same deed by a simple person. However, with regard to a prohibitive command — not to eat, drink, etc. — all Jews are equal in their observance.

Herein lies the difference between Nitzavim and Vayeilech. While both address the theme of Jewish unity, Nitzavim speaks of uniting disparate levels of Jews, while the unity spoken of in Vayeilech is such that all Jews are entirely equal.

Based on Likkutei Sichos, Vol. XIX, pp. 298-304.