This is courtesy of D. It is a bombardment of questions, with answers that tie and unify the themes of the questions.
The Orach Chaim asks at Shemos 3:5, when G-d reveals Himself to Moshe, why G-d waits until Moshe is on the mountain and at the burning bush (the bush was on Mt Sinai, this episode occurred there) to tell him he must take his shoes off as he is on sacred ground. But why not warn him before he climbs the mountain?
At 3:11, he asks “who am I take them out?”, and G-d responds (3:12) that “וַיֹּאמֶר כִּי אֶהְיֶה עִמָּךְ וְזֶה לְּךָ הָאוֹת כִּי אָנֹכִי שְׁלַחְתִּיךָ בְּהוֹצִיאֲךָ אֶת הָעָם מִמִּצְרַיִם תַּעַבְדוּן אֶת הָאֱ־לֹהִים עַל הָהָר הַזֶּה – And He said, “For I will be with you, and this is the sign for you that it was I Who sent you. When you take the people out of Egypt, you will worship God on this mountain.” “
The first question: how is this remotely helpful as a reply to a slave in Egpyt querying his would-be saviour’s legitimacy? It’s not a proof, it’s a statement about the future, but does not ascertain anything at the time the proof is warranted.
The second question, where does תַּעַבְדוּן – worship, enter the equation? Apart from their acceptance, weren’t the Jews entirely passive? What worship did they perform on Mt Sinai?
In Beshalach, 17:1, the pasuk informs us that when the Jews camped in Refidim, they had no water. 5 verses later, G-d tells Moses to strike a rock at Horeb (Mt Sinai). Refidim is far from Horeb, so what’s going on?
In Yisro, 19:12, instructions are issued to build a boundary around Mt Sinai, and the next pasuk specifies laws “לֹא תִגַּע בּוֹ יָד כִּי סָקוֹל יִסָּקֵל אוֹ יָרֹה יִיָּרֶה אִם בְּהֵמָה אִם אִישׁ לֹא יִחְיֶה בִּמְשֹׁךְ הַיֹּבֵל הֵמָּה יַעֲלוּ בָהָר – No hand shall touch it, for he shall be stoned or cast down; whether man or beast, he shall not live. When the ram’s horn (Shofar) sounds a long, drawn out blast, they may ascend the mountain.”
Why is it that no one, not even an animal, can stray into the mountain, nor were they even allowed to touch it 3 days before the Torah was given?
There is a concept with Kadshim (sacred items and laws) about there being a permit, a mattir, to use something something that was once Kodesh(sacred). Why is it that there is such a requirement here?
Lastly, after the Ten Commmandments, there is an instruction to build a Mizbeach Adama, an earthen altar (20:21). What is the connection between G-d giving us the Torah and building an altar there?
End of questions.
The Rambam (Maimonides) explains that all instance of G-d speaking to a person are through messengers/angels and the like. The only “face to face” meeting with G-d was with Moshe
To answer our question of why wait until he is there to tell him to remove the shoes, the answer is simple once pointed out; וַיֵּרָא מַלְאַךְ ה’ אֵלָיו בְּלַבַּת אֵשׁ מִתּוֹךְ הַסְּנֶה וַיַּרְא וְהִנֵּה הַסְּנֶה בֹּעֵר בָּאֵשׁ וְהַסְּנֶה אֵינֶנּוּ אֻכָּל – An angel of the Lord appeared to him in a flame of fire from within the thorn bush, and behold, the thorn bush was burning with fire, but the thorn bush was not being consumed.” (3:2)
Only at 3:4 does G-d appear – וַיַּרְא ה’ כִּי סָר לִרְאוֹת וַיִּקְרָא אֵלָיו אֱ־לֹהִים מִתּוֹךְ הַסְּנֶה וַיֹּאמֶר מֹשֶׁה מֹשֶׁה וַיֹּאמֶר הִנֵּנִי – The Lord saw that he had turned to see, and God called to him from within the thorn bush, and He said, “Moses, Moses!” And he said, “Here I am!”
So this explains why he was only warned once he was there; as he ascended, there was no prohibition, G-d wasn’t there, an angel was! Only once G-d appeared did the land become holy so he would need to take off his shoes.
Bearing in mind that the land itself, Mt Sinai, was already holy from that moment, we can further understand the “proof” that Moshe was meant to tell people, which Targum Yonasan ben Uziel explains at 19:5 that the mountain of G-d was the proof; that there was a place waiting for the Jews where the Torah would be given, and the Mishkan would be built, they were now a nation in waiting.
So it has been established that the land was holy before the Torah was given, and the Chizkuni explains that in Refidim, when they had no water, Moshe went to Horeb, and brought back a rock from there, and it was this rock from Mt Sinai that he struck to make water.
What about the permit/mattir to use the land? Where does that enter the equation? The Ibn Ezra quotes R’ Hai Gaon that the Shofar was blown when the command to build the Mishkan was given, and this Shofar, coupled with the sacrifices brought on the Mizbeach Adama (earthen altar), transferred the holiness from the mountain to the Mishkan .
So the mountain was forbidden and holy once G-d revealed Himself at the burning bush. In shachris (morning prayers), in the section regarding the sacrifices, we say “olas hatamid ka’asuya b’har sinai” that we bring the Tamid sacrifice like on Mt Sinai. So when did we bring sacrifices on Mt Sinai? At the time the Mishkan was consecrated for the first time, on Mt Sinai!
With this we can understand why the pasuk said תַּעַבְדוּן – worship. They did worship at Mt Sinai, when they consecrated the Mishkan by bringing the sacrifices, using the earthen altar and blowing the Shofar, which transferred the innate holiness of Mt Sinai that had been there since G-d had revealed himself to the Mishkan.
I think that ties up all the loose ends.