Chiddushei Torah
Rebbe Boruch'l of Mezhibuzh zt'l said that he is more afraid of Shavuos than Rosh Hashanah. On Rosh Hashanah, the judgment is on gashmiyos. So, it will be one more bilke (challah) or one less (it doesn't make much of a difference). But on Shavuos, the judgment is for Torah, and how much Torah one will receive that year. And therefore, he is more afraid of Shavuos.
We discussed above that every year, on Shavuos, Hashem once again gives us the Torah. One matan Torah occurred at Har Sinai, and a second type of matan Torah happens every Shavuos. There is also a third kind of matan Torah, which transpires daily.
The Tola'as Yaakov (quoted by the Shlah) says that האילן פירות represents Jewish souls. When the Gemara says that the judgment is for the האילן פירות, this means that on Shavuos, Yidden are judged for bittul Torah and for not being sufficiently devoted to keeping the mitzvos.
The pasuk (Shemos 19:19) says, מאוד וחזק הולך השופר קול ויהי, "The sound of the shofar was powerful..." The Or HaMeir zt'l teaches that חזק can also mean contains (see Eiruvin 14 – טהרה מקוה וחמישים מאה מחזיק היה שלמה שעשה ים). This implies that kabalas haTorah contains and holds all chiddushei Torah that will be revealed during the year. The Sfas Emes says that Shavuos is called בכורים יום, the yom tov of the new fruit. The new fruit represents the new Torah given to us on that day.
In birchas haTorah, we say התורה נותן, "Hashem, Who gives the Torah." It is written in the present tense because Hashem gives us the Torah every day. The Taz (Orach Chaim 47:5) says that this is because Hashem gives us the Torah daily, based on the amount of Torah we received that year on Shavuos.
What is the significance of these three matan Torahs? Derech HaMelech (from the Rebbe of Piasezcna zt'l) explains that we received the Torah on Har Sinai, and each year, on Shavuos, we receive the chidushei Torah that we can discover that particular year. However, on Shavuos, it is still a non-defined prophecy because one doesn't yet know the chidushim he will discover. When one studies Torah throughout the year, he brings forth the chidushei Torah he received on Shavuos. That is when he discovers what he received on Shavuos. These are the three matan Torahs. One is a general matan Torah, one is for the Torah he can receive that year, and each day, he receives the Torah again, the chidushim that he can acquire on that day.
Chazal (Rosh Hashanah 16.) say, "On Shavuos, there is a judgment for the fruits of the trees." The Sfas Emes explains that you are judged which chiddushim you will perceive that year on Shavuos. The Sfas Emes concludes, "Shavuos is the source of Torah for the entire year."
