Shavuot is the holiday when we received the Torah. It is commonly thought that this holiday is in honor of the Written Torah, which was given to us through the mouth of Hashem Himself. However, it seems that there is room to emphasize, no less and perhaps even more, the Oral Torah (Torah sheba'al peh) on Shavuot.
This idea is expressed in the language of the Midrash (Yalkut Shimoni, Shemot, 245): "The assembly of Israel said before the Holy One, Blessed be He: The words of the sages are more precious to me than the words of the Torah." Meaning, the words of the Sages of Israel are superior to the written words of the Torah.
In fact, the idea of Matan Torah (the giving of the Torah) is not even mentioned in the Written Torah with regards to Shavuot. In the Written Torah, the only thing mentioned regarding Shavuot is the bringing of the first fruits (Bikkurim) to Jerusalem, the Menachot, and the sacrifices. There is no mention at all of the giving of the Torah.
The Gemara in Menachot tells us that when Moshe Rabbeinu went up to heaven to receive the Torah, he found Hashem crowning the letters of the Torah. Moshe Rabbeinu asked Hashem why He was crowning the letters. Hashem responded that later on, there would be a great individual named Akiva ben Yosef, and he would learn many Halachot from every single letter.
Moshe was so impressed that he asked Hashem to please show him this great person (and to take him into the future to see him). Hashem took Moshe and put him in the eighth row from Rabi Akiva in one of his shiurs, but he could not understand anything and was very disappointed.
Then, a student asked Rabi Akiva why we fulfill a certain thing, and Rabi Akiva responded that this thing was something that we don’t know the reason for, and we have a tradition all the way from Moshe Rabbeinu to fulfill it. Only then was Moshe calmed.
This story is rather puzzling. Moshe Rabbeinu, who from him we received the entire Torah, is unable to understand a shiur from a rabbi many centuries later!? The answer is that the Torah constantly develops and grows throughout the years of its learning, just as long as it is within the principles that the Torah gives us to build upon itself.
Perhaps this is another reason why we read Megilat Rut on Chag Shavuot. If we would just follow the Written Torah, without Chazal's explanations and interpretations, we would not have the book of Tehilim that David HaMelech wrote, as we wouldn’t accept his great-grandmother, Ruth, as she came from the Moabite nation.
This is just one example, but there are many other examples from Chazal that show that without their words, we would not understand the Torah itself. This is why the Gemara in Masechet Makot says that all those who respect the Written Torah but mock the Oral Torah and its teachers are fools.
Every person here needs to realize that he has a mitzvah of developing the Torah and despite the fact that the Torah was written 3,300 years ago, it is always relevant and applies to each and every one of us, every single day. The Torah is eternal and endless, and everyone of us has a part of it.
As we celebrate Shavuot, let us embrace the timeless wisdom of the Torah and honor the tradition of our Sages. May we continue to learn, grow, and find inspiration in the eternal words of our heritage.
Chag Sameach!
Rabbi Eliyahu Tal