The Torah says in a number of places that the Jews received the Torah directly from Hashem. According to Rashi, Hashem told us the Asseret Hadibrot, the Decalogue, in one breath as only Hashem can do, and then He proceeded to explain it. On another Pasuk, Rashi comments that the people only heard the first two commandments directly and clearly from Hashem; since we were overwhelmed by Hashem’s voice, Hashem spoke and Moshe repeated the commandments to us. According to tradition, this is a large part of what we celebrate on Shavuot. But what exactly was it that we heard at Matan Torah?
Between Pesach and Shavuot, many follow the custom to study one Perek of Pirkei Avot each Shabbat afternoon. Rav Pinchas Kehati explains that the first of these Mishnayot, which states that Moshe “received the Torah from [Har] Sinai,” means that the entire Torah was received at Sinai, the written and the oral Torahs as one. This is based on a Pasuk in Parshat Bechukotai (Vayikra 26:46) that refers to the “statues, ordinances, and teachings that Hashem established between Himself and the children of Israel on Har Sinai by the hand of Moshe.” Rav Kehati explains the statutes are the Midrashim, the ordinances are the laws, and the teachings (“Torot”), which are named in the plural, are the two Torahs that were given to Bnei Yisrael, one written and one oral. R’ Kehati quotes Torat Kohanim that states that this demonstrates that the entire Torah, include its fine details, were given to Moshe at Har Sinai. The Mishna continues that Moshe passed it onto Yehoshua (Note: At Matan Torah, Yehoshua waited at Har Sinai waiting for Moshe to return); Yehoshua transmitted it to the elders, etc.
We all know that when Moshe Rabbeinu came down from Har Sinai: he witnessed the golden calf and immediately broke the Luchot. Moshe then returned to Har Sinai and received a second set, only this time, Moshe wrote the Luchot as Hashem dictated to him what to write. Rashi comments that Moshe was not allowed, however, to write the Oral Torah, which was to remain completely oral.
Rabbi Yehoshua ben Levi taught (Shabba 88b) that when Moshe went up to accept the Torah, the angels were upset that the Torah was being given to man and not to the angels. Moshe then proved to them that the contents were more fitting for humans than angels, and they agreed. The Beit HaLevi (D’rasha 18) comments that this discussion refers to the Oral Torah.
The Sefer Hatoda’ah, Book of our Heritage, points out that we need to learn both the Torah SheBichtav (Written Torah) and Torah Shebe’al Peh (Oral Torah) together. The example it cites is the story of Ruth, the Moabite, who was permitted to marry a Jew, and as a result, her descendant, David Hamelech, was anointed King for all generations. Although the Written Law states that a Moabite may not marry a Jew even after he converts, the Oral Law teaches that a female Moabite convert (such as Rut) may marry a Jew and that the prohibition presented in the Written Law applies only to a male Moabite.
On Shavuot, we celebrate both Torot, the Written and the Oral – both of which we received as completely integral parts of the Torah at Sinai.