As we are approaching the Yom Tov of Shavuos. here is a letter (translated from the Yiddish) that the Rebbe wrote regarding this Yom Tov and the preparations:
By the Grace of G-d
In the Days of Preparation to the Season of the Giving of our Torah, 5743.
Brooklyn, N.Y.
To the Sons and Daughters of
Our People Israel, Everywhere
G-d bless you all!
Greeting and Blessing:
In these auspicious days, certainly everyone will utilize these days that are designated for additional preparation for receiving Torah to prepare additionally well and with extra vigor in anticipation of the great day – “The day when you stood before the L-rd, your G-d, at Chorev” to receive the eternal Torah which shall never be substituted.
Explore and consider how our ancestors prepared in the lead-up to this day, beginning from that dramatic day when our teacher Moshe received the news that “When you will lead the people out of Egypt, you will worship G-d on this Mount,” meaning that the giving of the Torah on Mount Sinai was the ultimate goal of Yetzias Mitzrayim, from bondage to freedom, to be servants of Hashem and not servants of servants, including not servants of “the strange god (the yetzer hara) that is within you,” as only this constitutes true and complete freedom.
And it goes without saying that all the signs and miracles that they witnessed in Egypt and on the sea, which were in a manner of “affliction for Egypt, and healing for Israel,” amazed and directed their minds and hearts to their Father in Heaven with love and awe, “just as water mirrors a face to a face,” as the Alter Rebbe marvels about this topic in his book, the sacred Tanya, using the well-known parable of a great and mighty king who displays his great and intense love for a commoner, etc.
And immediately on the morrow of leaving Egypt with an “upraised arm,” they began to count the days and weeks longingly, desirously, and thirstily for that auspicious day upon which G-d would descend on Mount Sinai before their eyes and give them His hidden treasure. And they ascended in holiness from day to day in preparation for this event, all based on the guidance (and encouragement, urging, and assistance) of Moshe Rabbeinu, the Shepherd of Israel, the Faithful Shepherd from his time until this very day.
The Three Days of Preparation and the Festival of the Giving of our Torah indeed come once a year, but there is a small-scale version of this preparation and of Matan Torah every day. As is known, the explanation of the precise wording of the conclusion of birchas haTorah – recited in the morning blessings each day and likewise when receiving an aliyah to the Torah – is Nosein HaTorah, Giver of the Torah, in the present tense, meaning that each day the Torah is given anew, which automatically means that a preparation for this is also necessary, and indeed our Sages have said and instructed, “Every day they should be (as) new in your eyes.”
…Likewise with regard to the yearly Giving of the Torah and the Receiving of the Torah (and the Days of Preparation) in the third month – and from them a great influx flows and adds vitality and light in the fulfillment of the directive “they shall be (as) new in your eyes” – each and every day, throughout the duration of the day.
* * *
May G-d grant that each and every individual will complete all the preparations, and specifically in the Days of Preparation, and until the conclusion of the seven perfected weeks, and they shall receive the Torah with joy and pnimius [lit., innerness; connotes the endeavor to make our deeds an integral part of us] at the Season of the Giving of Our Torah,
And in the manner described, that it shall be drawn down and affect every single day of the entire year.
And in the immediate future will be fulfilled the promise: “Arise O G-d, judge the earth (with the judgment of our Torah, which is Divine judgment – “Judgment is compassion”), for You possess [rule] all the nations,” as it is written, “For then I will transform the nations to all call in Hashem’s Name, and serve Him with one consent,”
With the true and complete geulah through our righteous Mashiach.
With esteem and with blessing for success in all the aforementioned, and with blessing for a joyous holiday of Shavuos, and to receive the Torah with joy and pnimius,
Menachem Schneerson