(3) and Moses went up to God. The Eternal called to him from the mountain, saying, “Thus shall you say to the house of Jacob and declare to the children of Israel: (4) ‘You have seen what I did to the Egyptians, how I bore you on eagles’ wings and brought you to Me. (5) Now then, if you will obey Me faithfully and keep My covenant, you shall be My treasured possession among all the peoples. Indeed, all the earth is Mine, (6) but you shall be to Me a kingdom of priests and a holy nation.’ These are the words that you shall speak to the children of Israel.” (7) Moses came and summoned the elders of the people and put before them all that the Eternal had commanded him. (8) All the people answered as one, saying, “All that the Eternal has spoken we will do!” And Moses brought back the people’s words to the Eternal.
(Shemot 19:17) "They stood at the bottom of the mountain." Rav Avdimi bar Chama bar Chasa said: This teaches that the Holy One, Blessed be God, covered them with the mountain like an [overturned] vat. And God said to them, "If you accept the Torah, good. And if not, there will be your burial." Rav Acha bar Yaakov said, from here is a strong signal [of coercion] regarding [acceptance of] the Torah.
I believe with perfect faith that all of the torah which is in our hands today was given to Moses (at Sinai)
Maimonides 13 Principles of Faith #8
(46) These are the laws, rules, and instructions that the Eternal established, through Moses on Mount Sinai, between Himself and the Israelite people.
The Torot - we learn that there were two torot given to them, to Israel. One Written, one Oral
(sifra bechukotai)
The gemara gives two opinions: that Torah was written in installments, or that Torah was written at the end of the 40 years. There is no opinion that Moses had a fully written Torah at Mt Sinai.
(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.
Another interpretation: 'And God gave to Moses...' (Exodus 31:18) Rabbi Abahu said: All forty days that Moses was up there, he would learn Torah and then forget. He said to Him: Master of the Universe! It's been forty days and I don't know a thing! What did The Holy One do? When forty days were up, The Holy One gave him Torah as a gift, as it says, "And He gave to Moses..." And did Moses really learn the whole Torah? It's written in the Torah (Job 11): Her measure is longer than the Earth and broader than the sea. And Moses learned it in forty days?! Rather, The Holy One taught him the general principles. Hence, '...when He had finished speaking with him.'
. 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:
And Rabbi Levi Bar Chama said that Rabbi Shimon Ben Lakish said: Why does it say 'And I will give you the tablets of stone and the Torah and the Mitzvah that I have written to teach them.' (Exodus 24;12) The tablets- these are the ten utterances. Torah- this is the chumash. And the Mitzvah- this is the Mishna. That I have written- these are the Prophets and the Writings. To teach them--This is the Gemara This teaches you that all of them were given to Moses on Sinai.
אמר רב יהודה אמר רב בשעה שעלה משה למרום מצאו להקב"ה שיושב וקושר כתרים לאותיות אמר לפניו רבש"ע מי מעכב על ידך אמר לו אדם אחד יש שעתיד להיות בסוף כמה דורות ועקיבא בן יוסף שמו שעתיד לדרוש על כל קוץ וקוץ תילין תילין של הלכות אמר לפניו רבש"ע הראהו לי אמר לו חזור לאחורך הלך וישב בסוף שמונה שורות ולא היה יודע מה הן אומרים תשש כחו כיון שהגיע לדבר אחד אמרו לו תלמידיו רבי מנין לך אמר להן הלכה למשה מסיני
Rav Yehuda said that Rav said: When Moses went up to the heights, he found The Holy One sitting and attaching crowns to the letters. He said before Him, "Master of the Universe, who is delaying your hand?" He said to him, "There is one man who will come in the future, after a number of generations, and his name is Akiva Ben Yosef, who will drash each and every tittle mounds and mounds of halachot.". He said before Him, "Master of the Universe, show him to me!" He said, "Turn around!" He went and he sat in the eighth row and he didn't know what they were saying. He was upset. When they arrived a certain point, his students said to him, "Rabbi, where did you get this from? ". He said to them, "It's a halacha [given] to Moses on Sinai." His mind was put at ease.
(from the Introduction to Dor Revi’i by R’ Moshe Glasner (1856-1924)
(יא) כִּ֚י הַמִּצְוָ֣ה הַזֹּ֔את אֲשֶׁ֛ר אָנֹכִ֥י מְצַוְּךָ֖ הַיּ֑וֹם לֹֽא־נִפְלֵ֥את הִוא֙ מִמְּךָ֔ וְלֹ֥א רְחֹקָ֖ה הִֽוא׃ (יב) לֹ֥א בַשָּׁמַ֖יִם הִ֑וא לֵאמֹ֗ר מִ֣י יַעֲלֶה־לָּ֤נוּ הַשָּׁמַ֙יְמָה֙ וְיִקָּחֶ֣הָ לָּ֔נוּ וְיַשְׁמִעֵ֥נוּ אֹתָ֖הּ וְנַעֲשֶֽׂנָּה׃ (יג) וְלֹֽא־מֵעֵ֥בֶר לַיָּ֖ם הִ֑וא לֵאמֹ֗ר מִ֣י יַעֲבָר־לָ֜נוּ אֶל־עֵ֤בֶר הַיָּם֙ וְיִקָּחֶ֣הָ לָּ֔נוּ וְיַשְׁמִעֵ֥נוּ אֹתָ֖הּ וְנַעֲשֶֽׂנָּה׃ (יד) כִּֽי־קָר֥וֹב אֵלֶ֛יךָ הַדָּבָ֖ר מְאֹ֑ד בְּפִ֥יךָ וּבִֽלְבָבְךָ֖ לַעֲשֹׂתֽוֹ׃ (ס)
(11) Surely, this Instruction which I enjoin upon you this day is not too baffling for you, nor is it beyond reach. (12) It is not in the heavens, that you should say, “Who among us can go up to the heavens and get it for us and impart it to us, that we may observe it?” (13) Neither is it beyond the sea, that you should say, “Who among us can cross to the other side of the sea and get it for us and impart it to us, that we may observe it?” (14) No, the thing is very close to you, in your mouth and in your heart, to observe it.
(א) משֶׁה קִבֵּל תּוֹרָה מִסִּינַי, וּמְסָרָהּ לִיהוֹשֻׁעַ, וִיהוֹשֻׁעַ לִזְקֵנִים, וּזְקֵנִים לִנְבִיאִים, וּנְבִיאִים מְסָרוּהָ לְאַנְשֵׁי כְנֶסֶת הַגְּדוֹלָה. הֵם אָמְרוּ שְׁלשָׁה דְבָרִים, הֱווּ מְתוּנִים בַּדִּין, וְהַעֲמִידוּ תַלְמִידִים הַרְבֵּה, וַעֲשׂוּ סְיָג לַתּוֹרָה:
(1) Moses received the Torah from Sinai, and transmitted it to Yehoshua, and Yehoshua to the Elders, and the Elders to the Prophets, and the Prophets transmitted it to the Men of the Great Assembly. They said three things: Be deliberate in judgment, and establish many students, and make a fence for the Torah.
When defining the terms of the expression Torah min hashamayim, ‘Torah from Heaven’, he notes that nowhere in the Pentateuch is the word ‘Torah’ used to refer to the five books of Moses. Such a designation, as a matter of fact, dates back to the rabbinic period. Similarly, the statement traditionally recited after the reading of the Torah in synagogue – ‘And this is the Torah which Moses placed before the children of Israel, according to the word of God and the hand of Moses’ – is a medieval amalgamation of two biblical verses, which taken separately do not convey such an idea.
For many of us, questions of authorship – or, indeed, of historicity – are irrelevant to our relationship with Torah. This is our people’s story, our literature, our poetry, our law. This is the formative stuff of our religious and cultural lives. The relationship with Torah is a deeply intimate, and particularistic one because it is ours. Like all good relationships, for Reform Jews it can be a critical relationship, too. (J.Levy)