The maamar proceeds to offer another explanation why Rosh Chodesh Sivan served as the beginning of the final stage of the Jewish people’s preparation for receiving the Torah:וּמַמְשִׁיךְ בְּהַמַּאֲמָר עוֹד בֵּאוּר בָּזֶה שֶׁבְּרֹאשׁ חֹדֶשׁ סִיוָן הוּא הַהֲכָנָה לְקַבָּלַת הַתּוֹרָה,
After the exodus of the Jewish people from Egypt, they began counting the Omer,דִּבְצֵאת יִשְׂרָאֵל מִמִּצְרַיִם הִתְחִילוּ לִסְפֹּר סְפִירַת הָעֹמֶר,
This is the wording in Torah Or. True, the actual mitzvah of the Counting of the Omer was commanded only at a later stage. Nevertheless, it is possible to explain that the intent is the spiritual service that is the counterpart of that mitzvah.
which served as preparation for receiving the Torah.שֶׁהִיא הֲכָנָה לְקַבָּלַת הַתּוֹרָה,
The seven weeks of the Counting of the Omerוְז' הַשָּׁבֻעוֹת דִּסְפִירַת הָעֹמֶר
(as it is written,1 “You shall count seven weeks,”)(שִׁבְעָה שָׁבֻעוֹת תִּסְפָּר לָךְ)
correspond to the seven emotive attributes.הֵם כְּנֶגֶד ז' הַמִּדּוֹת,
As explained in the previous section, each week is associated both with the revelation of one of these emotive attributes from Above, and similarly, with man’s efforts to refine and develop the expression of that emotional attribute within his own character.
On Rosh Chodesh Sivan, the third day of the seventh week,וּבְרֹאשׁ חֹדֶשׁ סִיוָן שֶׁהוּא יוֹם הַג' דְּשָׁבוּעַ הַז'
the Divine service associated with the first three emotive attributes – Chessed, Gevurah, and Tiferes – has already been completedיֶשְׁנָם כְּבָר ג' הַמִּדּוֹת חֶסֶד גְּבוּרָה תִּפְאֶרֶת
(these being the primary emotive attributes)(שֶׁהֵם עִקְּרֵי הַמִּדּוֹת)
As explained in Chassidus,2 all the other emotive attributes derive from these three.
of the Sefirah of Malchus, which is the Sefirah associated with the seventh week of the Counting of the Omer.דִּסְפִירַת הַמַּלְכוּת,
Thus, it is as if the entire Divine service to be carried out in the seventh week has already been completed. Hence, man’s efforts to refine his character are considered to have been consummated by this day.וּכְאִלּוּ שֶׁיֶּשְׁנוֹ כְּבָר כָּל שָׁבוּעַ הַז',
Therefore, on Rosh Chodesh Sivan, the Jewish people “came to the Sinai desert,” i.e., they were ready to receive the Torah,וְלָכֵן בְּרֹאשׁ חֹדֶשׁ סִיוָן בָּאוּ מִדְבַּר סִינָי
for it was then, with the refinement of these seven emotional attributes, that the fundamental preparation for the Giving of the Torah was completed.כִּי אָז נִשְׁלַם עִקַּר הַהֲכָנָה לְמַתַּן תּוֹרָה.
It is possible to explain that the reason that the maamar in Torah Or offers two explanations why Rosh Chodesh Sivan represents the final stage in preparing for receiving the Torah3וְיֵשׁ לוֹמַר, דְּזֶה שֶׁמְּבָאֵר בְּהַמַּאֲמָר שְׁנֵי בֵּאוּרִים בָּזֶה שֶׁבְּרֹאשׁ חֹדֶשׁ סִיוָן הוּא הַהֲכָנָה לְקַבָּלַת הַתּוֹרָה,
is because there are two distinct aspects necessary in man’s preparation to receive the Torah:הוּא, כִּי בְּהַהֲכָנָה לְקַבָּלַת הַתּוֹרָה שְׁנֵי עִנְיָנִים.
a) that man reach a state of shleimus, “perfection,”הַשְּׁלֵמוּת דְּהָאָדָם,
for to be fit to accept the Torah, man must reach a state of ultimate perfection;שֶׁבִּכְדֵי שֶׁיִּהְיֶה רָאוּי לְקַבֵּל הַתּוֹרָה צָרִיךְ לִהְיוֹת בְּתַכְלִית הַשְּׁלֵמוּת.
Our Sages4 thus quote G‑d as saying: “It is not befitting that I give My Torah to blemished people”;
and b) his attainment of bittul. To explain why bittul is necessary:וְהַבִּטּוּל שֶׁלּוֹ.
Since the Torah is incomparably loftier than a human being,דְּכֵיוָן שֶׁהַתּוֹרָה הִיא לְמַעְלָה בְּאֵין עֲרֹךְ מֵהָאָדָם
(which can be understood from the fact that it is even loftier than all the supernal spiritual worlds,)(בְּמִכָּל שֶׁכֵּן מִזֶּה שֶׁהִיא לְמַעְלָה מֵעוֹלָמוֹת הָעֶלְיוֹנִים),
accordingly, when a person is concerned with his own identity, he is a yesh and a metziyus in chassidic terminology,לָכֵן, כַּאֲשֶׁר הָאָדָם הוּא מְצִיאוּת,
his personal identity is (as it were) in opposition to the Torah.הַמְּצִיאוּת שֶׁלּוֹ הִיא (כְּמוֹ) הֵפֶךְ הַתּוֹרָה,
Thus our Sages comment5 on the verse,6 “It [the Torah] is not in the heavens,” that “It will not be found among the haughty.” And they say,7 “Whenever a person is characterized by haughtiness, the Holy One, blessed be He, says, ‘He and I cannot coexist in the world.’ ”
The manner in which a person makes himself fit to receive the Torah is through bittul.וּבִכְדֵי שֶׁהָאָדָם יְקַבֵּל אֶת הַתּוֹרָה הוּא עַל יְדֵי הַבִּטּוּל שֶׁלּוֹ.
Accordingly, the maamar in Torah Or explains that the reason that it was on Rosh Chodesh Sivan that the Jewish people came to the Sinai desertוְלָכֵן מְבָאֵר בְּהַמַּאֲמָר, דְּזֶה שֶׁבְּרֹאשׁ חֹדֶשׁ סִיוָן בָּאוּ מִדְבַּר סִינָי
and were prepared to receive the Torah isוְהָיוּ מוּכָנִים לְקַבֵּל הַתּוֹרָה, הוּא,
because Rosh Chodesh Sivan reflects both of these dimensions:כִּי בְּרֹאשׁ חֹדֶשׁ סִיוָן יֶשְׁנָם שְׁנֵי הָעִנְיָנִים.
a) Rosh Chodesh represents the birth of the new moon,זֶה שֶׁבְּרֹאשׁ חֹדֶשׁ הוּא מוֹלַד הַלְּבָנָה,
when it is merely a point, emphasizing the quality of bittul;שֶׁאָז הִיא נְקֻדָּה בִּלְבָד, בִּטּוּל.
and b) On Rosh Chodesh Sivan, the Divine service associated with refining the primary dimension of our emotions is completed,וְזֶה שֶׁבְּרֹאשׁ חֹדֶשׁ סִיוָן נִשְׁלְמוּ עִקְּרֵי הַמִּדּוֹת
including (also) the sefirah of Malchus,(גַּם) בִּסְפִירַת הַמַּלְכוּת –
this refinement reflects man’s shleimus.שְׁלֵמוּת הָאָדָם.
More particularly, there are two aspects of man’s shleimus achieved through the Divine service of Counting the Omer:וּשְׁנֵי עִנְיָנִים בְּהַשְּׁלֵמוּת דְּהָאָדָם שֶׁנַּעֲשֵׂית עַל יְדֵי סְפִירַת הָעֹמֶר.
a) Counting the Omer represents the refinement and purification of our emotions;שֶׁסְּפִירַת הָעֹמֶר הוּא עִנְיַן בֵּרוּר וְזִכּוּךְ הַמִּדּוֹת,
and b) through the Counting of the Omer, the 49 Gates of Understanding are drawn down from Above.וְשֶׁעַל יְדֵי סְפִירַת הָעֹמֶר הוּא הַמְשָׁכַת מ"ט שַׁעֲרֵי בִינָה.
It is possible to explain that the refinement and purification of the emotions is necessary so that man will not be lacking or blemished, and it is necessary to draw down the 49 Gates of Understanding to accomplish perfection (to create a “perfect place”) that will serve as a medium for the 50th Gate of Understanding.8

Summary

There is another explanation why Rosh Chodesh Sivan served as the beginning of the final stage of preparation for receiving the Torah: After the Exodus, the Jewish people began carrying out Divine service that paralleled the Counting of the Omer.
The seven weeks of the Counting of the Omer are dedicated to the refinement of man’s seven emotional attributes. On Rosh Chodesh Sivan, the third day of the seventh, final week, the Divine service associated with the refinement of the three primary emotive attributes, Chessed, Gevurah, and Tiferes, of the sefirah of Malchus was completed.
Rosh Chodesh Sivan thus reflects two dimensions:
a) the birth of the new moon, emphasizing the quality of bittul; and
b) the completion of the Divine service associated with refining the emotions.
Both these aspects are fundamental because there are two requisite aspects of man’s preparation to receive the Torah:
a) that man reach a state of shleimus, “perfection,” for it is not befitting to give the Torah to one who is blemished; and
b) that he attain bittul, for a person concerned with his own identity – a yesh in chassidic terminology – is (as it were) incompatible with the Torah.