The Rebbe explains that
Matan Torah, the Giving of the Torah, is supposed to be an eternal teaching. It's not just a holiday that we celebrate annually to commemorate an historical event. Every year we have to
live with
Matan Torah as an event here and now.
What does Matan Torah teach us? One of the best places to look for an answer is in Pirkei Avos because that is what our Sages have established as the best preparation for receiving the Torah -- to learn the six chapters of Pirkei Avos during the six Shabbosos between Pesach and Shavuos.
We will examine the first mishnah of Pirkei Avos, because the first in a series always has importance in its own right, and that is why it was placed first. What does the first mishnah of Pirkei Avos state? That Moshe received the Torah at Sinai and gave it to Yehoshua. The lesson is that as soon as you get the Torah, you must give it over to somebody else. Moshe didn't say, "Lucky me, I got the Torah; I'm going to sit and learn and enjoy it all by myself." The first thing Moshe did, as soon as he got the Torah from HaShem, was to give it over to his disciple, Yehoshua. The love that Moshe Rabbeinu had for his fellow Jews compelled him to share with them the Torah he received.
Although Pirkei Avos mentions only that he gave over the Torah to Yehoshua, anyone who learns Chumash knows that he also taught it to Aharon and his sons and then he taught it to the seventy elders, and so on. In turn, they also taught it to others. In other words, this was the idea behind receiving the Torah. You receive it in order to impart it to others.
This is the idea of being a lamplighter. You do not keep anything for yourself. You have Torah? That's great! Now share it with somebody.
Another point that the Rebbe makes is that nothing should be left in the abstract. When Torah remains in the realm of philosophy, or even of study without practice, then it's like a secular subject. When someone goes to college to learn calculus or botany, he doesn't expect it to change his life, he just wants to get a good mark on his exams. He likes the subject, but it doesn't make him a moral person. Don't we all know that! Botany doesn't make a person moral, it doesn't make him kind, it doesn't make him a nice husband or anything like that. It's just there in the brain. But, the Rebbe says, if Torah remains an intellectual pursuit, the acquisition of facts, then it's not Torah, it's a subject in school. Torah has to affect the way you feel, the way you think, the way you speak -- and most importantly, the way you act.
The festival of Shavuos is closely intertwined with three very famous personalities in the Torah. One is Moshe Rabbeinu, who gave us the Torah. The second one is David HaMelech, who passed away on Shavuos, and the third one is the Baal Shem Tov, who also passed away on Shavuos. Each of these three individuals is connected with a very important work in the Torah. Moshe Rabbeinu is connected with the Chumash, with the five Chumashim that he gave, that he wrote, that he taught. David HaMelech, as we all know, is synonymous with the Sefer Tehillim. The Baal Shem Tov gave us Toras HaChassidus, which is encapsulated in the Tanya, written by the Alter Rebbe two generations after the Baal Shem Tov.
The Previous Rebbe, Rabbi Yosef Yitzchak Schneersohn, inaugurated and initiated the custom of learning a little from each of these works every day. It is obvious to those of us who are close to the Rebbe that it is to our utmost benefit in gashmiyus and in ruchniyus, on physical and spiritual planes, to observe this custom, because the Rebbe has indicated on numerous occasions that saying every day the daily portion of Chumash, Tehillim and Tanya is a channel, a vessel, for spiritual and physical blessings. This is the actualization of receiving the Torah -- to bring it into your daily life through fulfilling the custom of reciting Chitas, as it is called (an acronym for Chumash, Tehillim, and Tanya). Take this custom upon yourself, and you will surely fulfill the idea of Matan Torah in the most practical sense.