שמות פרק כד, יב וַיֹאמֶּר ה' אֶּל-משֶּה עֲלֵה אֵלַי הָהָרָה וֶּהְׁיֵה-שָם וְׁאֶּתְׁנָה לְׁךָ אֶּת - לֻחֹת הָאֶּבֶּן וְׁהַתוֹרָה וְׁהַמִּצְׁוָה אֲשֶּר כָתַבְׁתִי לְׁהוֹרֹתָם :
מסכת ברכות דף ה/א אמר ר' שמעון בן לקיש מאי דכתיב ואתנה לך את לוחות האבן והתורה והמצוה אשר כתבתי להורותם לוחות אלו עשרת הדברות תורה זה מקרא והמצוה זו משנה אשר כתבתי אלו נביאים וכתובים להורותם זה גמרא מלמד שכולם נתנו למשה מסיני:
All the main points of Torah and halacha that future rabbis and students would derive by the way of pilpul, derivations, and allusions, would already be included in the Torah from the beginning. However, this is not meant to imply that everything that future generations would innovate in the learning of Torah would have already been revealed to Moshe at Sinai. Since that understanding would “put down” all the life work and striving of so many throughout history to clarify and derive clear understanding of Torah.
This is the proper understanding of this concept as evidenced in the famous Medrosh where G-d showed Moshe the Yeshivah of Rabbi Akiva. At first, Moshe was disheartened since he did not understand the sources for the laws that Rabbi Akiva derived. But Moshe was assuaged when he heard that Rabbi Akiva learned the laws from the crowns on the letters, and this became “halacha to Moshe from Sinai.” Thus, Moshe understood that the later laws were derived from what was revealed to Moshe.
