The Alter Rebbe states in his Shulchan Aruch1 that the custom is neither to fast nor recite the daily penitential prayers (Tachanun) from the beginning of Sivan through the twelfth of the month.

The Alter Rebbe cites the following reason for not reciting Tachanun:

“For immediately after Rosh Chodesh [Sivan], Moshe began occupying himself with them, [i.e., the Jewishpeople,] with regard to receiving the Torah. ...On Tuesday [the second of Sivan], he told them,2 ‘You shall be unto Me a kingdom of priests, etc.’; on Wednesday he commanded them3 ... not to ascend the mountain; on Thursday he commanded them4 to separate from their wives ... to be prepared for the ‘third day,’ the day of Shabbos, when the Torah was given.”

Although the Alter Rebbe’s source is the Magen Avraham,5 the Alter Rebbe changes the Magen Avraham’s wording. The Magen Avraham writes that “immediately, on the second of Sivan,Moshe began to sanctify them for the Torah,” while the Alter Rebbe states, “immediately after Rosh Chodesh Moshe began occupying himself with them with regard to receiving the Torah.”

By doing so, the Alter Rebbe elucidates that the significance of these days lies in their being days of “receiving the Torah.” For with regard to Torah there is the aspect of G‑d’s “giving the Torah,” Matan Torah, and our “receiving the Torah.” Although, generally speaking, receiving the Torah results from G‑d’s giving it to us, still, in a more profound sense, our receiving the Torah began even before G‑d gave it to us, as shall presently be explained.

Since the Alter Rebbe specifies these as days of “receiving the Torah,” it follows that each day had its own unique aspect: On the second of Sivan “receiving the Torah” involved the aspect of “You shall be a kingdom of priests”; on the third of Sivan “receiving the Torah” consisted of not ascending the mountain; on the fourth of Sivan “receiving the Torah” was comprised of“separating from their wives.”

These three aspects are similar to the elements of Matan Torah itself: The fundamental aspect of Matan Torah was G‑d’s descent below: the revelation of the Shechinah, the Divine Presence. The purpose of Matan Torah is peace, as the Rambam states,6 “The entire Torah was given to bring peace to the world.”

This aspect of “peace” refers not only7 to peace between men, but also between G‑d and His world. This “peace” is achieved by transforming the world into a vessel for G‑dliness, for then the world is “at peace” with Him, rather than it remaining in its natural oppositional state to G‑dliness. Thus the Jewishpeople are called “Shulamis” — from the root word shalom, peace — for, as G‑d said, by receiving the Torah, “they made peace between Me and My world.”8

There are two distinct aspects to peace:9 a) a negation of divisiveness and b) bringing about unity. So, too, with regard to the peace that was effected between G‑d and His world through Torah:

Torah, through its prohibitive commandments, brought about the negation of those things that are in opposition to G‑dliness. Through its positive commandments, Torah also established that matters were performed in accordance with G‑d’s will.

The three aspects of “receiving the Torah,” i.e., “a kingdom of priests,” “not ascending the mountain,” and “separation,” mirror this theme as well:

In spiritual terms, “not ascending the mountain,” means that one’s spiritual ascent should not be so totally unbounded that he completely divorces himself from material matters. Rather, G‑d desires that the world itself become a fit dwelling for Him,10 that the world be in total harmony with the dictates of Torah. This manner of service is similar to the raison d’être of the positive commands — drawing down holiness into this world.

On the other hand, when one does occupy himself with material matters, he must forewarn that he not become so immersed in them that they cause him to spiritually decline. This is the aspect of “separation,” corresponding to the prohibitive commands.

As a preparation to these two aspects of receiving the Torah, Moshe told the Jewishpeople on the second of Sivan, “You shall be unto Me a kingdom of priests and a holy nation.” This is not a command but a statement of fact — the Jewishpeople became an exalted “kingdom of priests,” capable of serving G‑d in the most profound manner possible.

This aspect of “receiving the Torah” served as the preparatory step to the two aspects of “receiving the Torah” that followed — that the Jewish people not ascend too high, nor descend too low. This motif was similar to that of G‑d’s giving of the Torah, wherein the descent of the Divine Presence into this world made possible the two aspects of “peace” — the positive and prohibitory commandments of the Torah.

* * *

We are enjoined not only to recount the past, but to relive it. It follows that just as every year the Torah is given anew, and moreover, on an even loftier level than before,11 the same is true regarding our preparations to Matan Torah:

In order to receive the Torah in the optimum manner, our preparations during the days leading up to Shavuos and Matan Torah should emulate the preparations of the Jewishpeople for the first Matan Torah.

Which is to say, that not only are we to increase our Torah study during these days, we are also to bring about the three above-mentioned aspects of “receiving the Torah” in our own lives, as well as in the lives of our fellow Jews.

Based on Likkutei Sichos, Vol. XXXVIII, pp. 1-6.