אֲנִי מַאֲמִין בֶּאֱמוּנָה שְׁלֵמָה, שֶׁכָּל הַתּורָה הַמְּצוּיָה עַתָּה בְיָדֵינוּ הִיא הַנְּתוּנָה לְמשֶׁה רַבֵּנוּ עָלָיו הַשָּׁלום.
Maimonides' 8th Principle of Faith
I believe with perfect faith that the entire Torah that we now have is that which was given to Moses.
What does this mean? How could all of Torah been given to Moshe on Har Sinai?
(יב) וַיֹּ֨אמֶר ה' אֶל־מֹשֶׁ֗ה עֲלֵ֥ה אֵלַ֛י הָהָ֖רָה וֶהְיֵה־שָׁ֑ם וְאֶתְּנָ֨ה לְךָ֜ אֶת־לֻחֹ֣ת הָאֶ֗בֶן וְהַתּוֹרָה֙ וְהַמִּצְוָ֔ה אֲשֶׁ֥ר כָּתַ֖בְתִּי לְהוֹרֹתָֽם׃
(12) And the LORD said unto Moses: ‘Come up to Me into the mount and be there; and I will give thee the tables of stone, and the law (Torah), and the commandment (mitzvah), which I have written, so that thou may teach them.’
וא"ר לוי בר חמא אמר ר' שמעון בן לקיש מאי דכתיב (שמות כד, יב)"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:
R. Levi b. Hamma also said in the name of R. Simeon b. Lakish : What means that which is written, "And I will give thee the tables of stone, and the law and the commandment, which I have written, that thou mayest teach them" (Exod. 24:12)? "Tablets of stone," i.e. the Decalogue: "law (Torah)," i.e. the Pentateuch; "commandment," i.e. the Mishnah ; "which I have written," i.e. the Prophets and Hagiographa; "that thou mayest teach them," i.e. the Gemara. The verse teaches that all of them were given to Moses on Sinai.
הקדמת הרמב"ם ז"ל
1. כל המצות שניתנו לו למשה בסיני בפירושן ניתנו. שנאמר ואתנה לך את לוחות האבן והתורה והמצוה. תורה זו תורה שבכתב. והמצוה זו פירושה. וצונו לעשות התורה על פי המצוה. ומצוה זו היא הנקראת תורה שבעל פה.
2. כל התורה כתבה משה רבינו קודם שימות בכתב ידו. ונתן ספר לכל שבט ושבט וספר אחד נתנהו בארון לעד. שנאמר לקוח את ספר התורה הזה ושמתם אותו וגו'.
3. והמצוה שהיא פירוש התורה לא כתבה אלא צוה בה לזקנים וליהושע ולשאר כל ישראל. שנאמר את כל הדבר אשר אנכי מצוה אתכם אותו תשמרו לעשות וגו'. ומפני זה נקראת תורה שבעל פה.
4. אף על פי שלא נכתבה תורה שבעל פה למדה משה רבינו כולה בבית דינו לשבעים זקנים. ואלעזר ופנחס ויהושע שלשתן קבלו ממשה.
Rambam, Introductions to Mishneh Torah (1177 CE)
1. The mitzvot given to Moses at Mount Sinai were all given together with their explanations, as implied by [Exodus 24:12]: "And I will give you the tablets of stone, the Torah, and the mitzvah." "The Torah" refers to the Written Law; "the mitzvah," to its explanation. [God] commanded us to fulfill "the Torah" according to [the instructions of] "the mitzvah." "The mitzvah" is called the Oral Law.
2. Moses, our teacher, personally transcribed the entire Torah before he died. He gave a Torah scroll to each tribe and placed another scroll in the ark as a testimonial, as [Deuteronomy 31:26] states: "Take this Torah scroll and place it [beside the ark...] and it will be there as a testimonial."
3. "The mitzvah" - i.e., the explanation of the Torah - he did not transcribe. Instead, he commanded it [verbally] to the elders, to Joshua, and to the totality of Israel, as [Deuteronomy 13:1] states: "Be careful to observe everything that I prescribe to you." For this reason, it is called the Oral Law.
4. Even though the Oral Law was not transcribed, Moses, our teacher, taught it in its entirety in his court to the seventy elders. Elazar, Pinchas, and Joshua received the tradition from Moses. [In particular, Moses] transmitted the Oral Law to Joshua, who was his [primary] disciple, and instructed him regarding it.
(ו) דבר אחר: ויתן אל משה אמר ר' אבהו: כל מ' יום, שעשה משה למעלה, היה למד תורה ושוכח. אמר לו: רבון העולם! יש לי מ' יום ואיני יודע דבר. מה עשה הקב"ה? משהשלים מ' יום, נתן לו הקב"ה את התורה מתנה, שנאמר: ויתן אל משה. וכי כל התורה למד משה?! כתיב בתורה (איוב יא): ארוכה מארץ מדה ורחבה מני ים, ולארבעים יום למדה משה?! אלא כללים למדהו הקב"ה למשה. הוי, ככלותו לדבר אתו.
(6) Another [understanding]: "And He gave it to Moshe" - Rabbi Abahu said, "All of the forty days that Moshe spent above, he would learn Torah and forget [it]. He said to Him, 'Master of the World, I have forty days and I do not know a thing.' What did the Holy One, blessed be He, do? As he finished the forty days, the Holy One, blessed be He, gave it to him as a gift, as it is stated, 'And He gave it to Moshe.'" And did Moshe learn the entire Torah? It is written [about] the Torah (Job 11:9), "It is longer than the Earth in size, and wider than the sea" – and in forty days Moshe learned it? But rather the Holy One, blessed be He, taught it to Moshe in its general principles (kelalim). This is [the meaning of] "when He finished (kekhaloto) speaking with him."
ר' ישמעאל אומר כללות נאמרו בסיני ופרטות באהל מועד. ור' עקיבא אומר כללות ופרטות נאמרו בסיני, ונשנו באהל מועד, ונשתלשו בערבות מואב.
R. Yishmael said, "General principles were told over at Sinai, and the details in the tent of meeting." But R. Akiva said, " [Both the] general principles and details were told over at Sinai, and they were repeated in the tent of meeting, and given for the third time in the plains of Moav."
אמר ר' חייא בר אבא א"ר יוחנן מאי דכתיב (דברים ט, י) "ועליהם ככל הדברים אשר דבר ה' עמכם בהר." מלמד שהראהו הקב"ה למשה דקדוקי תורה ודקדוקי סופרים ומה שהסופרים עתידין לחדש ומאי ניהו מקרא מגילה:
R. Hiyya b. Abba also said in the name of R. Yohanan: What is the meaning of what is written, "And on them was written according to all the words which the Lord spoke with you in the Mount” (Deuteronomy 9:10)? It teaches us that the Holy One, blessed be He, showed Moses the minute details of the Torah, and the minute details of the Scribes, and the innovations which would be introduced by the Scribes; and what are these? The reading of the Megillah.
מלמד שהראהו הקדוש ברוך הוא למשה דקדוקי תורה ודקדוקי סופרים ומה שהסופרים עתידין לחדש ומאי ניהו מקרא מגלה. דקדוקי סופרים הם המחלוקות וחילוקי הסברות שבין חכמי ישראל, וכולן למדם משה מפי הגבורה, ומסר בו כלל אשר בו יודע האמת, והוא אחרי רבים להטות (שמות כג ב), וכן לא תסור מן הדבר אשר יגידו לך (דברים יז יא).
Rabbi Nissim of Gerona (Barcelona 1320-1380), Derashot Ha’Ran, Derasha #5
The 'details' provided by the rabbis are halakhic disputes and conflicting views held by the sages of Israel. Moses learned them all by divine word with no resolution every controversy in detail. Yet [God] also gave him a rule whose truth is manifest, i.e., 'Favor the majority opinion'....as the sages of that generation saw fit, for the decision had already been delegated to them as it is written: 'And you shall come to the priest the Levites , and to the judge that shall be in those days' and 'You shall not deviate....".
These and these are the words of the living God'. The French Rabbis of blessed memory asked how it were possible that both positions could be the words of the living God when one prohibits and the other permits, and they answered: When Moses ascended to heaven to receive that Torah they have shown him forty nine reasons for prohibition and forty nine reasons for permission concerning each rule. He asked God about this and God answered that the matter will be given to the sages of Israel in each generation and the ruling will be as they decide.
For just as in natural science a person produces innovations with his intelligence and understanding based on old principles, so too with the science of our holy Torah. As Hazal say, "if you hear the old, you will hear the new." The intent is that one who incessantly occupies himself with the Torah that is with us of old and "kills himself over it", can derive totally new insights which were never (apprehended) before; it is in this sense that Hazal said that "the Holy One, blessed be He, showed Moses all that an experienced disciple would in future times innovate (in Torah)," for all that is destined to be innovated in Torah was inherent in potentia 1 (from the beginning)
• A full package of Oral Law including all 613 mitzvot and the details which are needed to keep them
• The ‘klalim’ for how to derive all future mitzvot min HaTorah
• He also had a full prophecy of the progress of Jewish history and of Torah chiddushim which would be generated in the future, but this was not passed on to us .
It seems that he did not receive the following:-
• All of the derashot which link the halachot with the pesukim
• Halachot derived later through ‘drash’ and ‘sevara’
• Rabbinic laws