Why, unlike the first Luchos, was nobody allowed to accompany Moshe onto Har Sinai for the second Luchos?
Rashi: Since the first Luchos were given with fanfare, with noise and gatherings of people, they were subject to Ayin ha'Ra. There is nothing nicer than modesty. 1
Ramban and Moshav Zekenim: Because the first Luchos were due to Yisrael's merit. The latter were due to the merit and Davener of Moshe alone.
Therefore the second Luchos were given without pomp and ceremony.
Seeing as the first Luchos were subject to Ayin ha'Ra, as Rashi explains, why did Hashem give them with such fanfare?
To practically teach Yisrael the hazards of publicity and the importance of Tzeniyus.
Oznayim la'Torah: Because the first Luchos were given when they had just left Egypt and in order to accept upon themselves the yoke of Torah and Mitzvos, they required the injection of Yir'as Shamayim that the thunder and lightning provided - despite the Ayin ha'Ra that accompanied it; whereas when the second Luchos, which were given after they had said to Moshe 'Hein Her'anu Hashem Elokeinu es Kevodo ve'es Kolo Shama'nu mi'Toch ha'Eish", that was not necessary.
Because of the powerful lessons , including Yir'as Shamayim, 1 that Yisrael gleaned from Hashem's Revelation at Matan Torah 2 .
Which is why the Torah (in Va'eschnan, Devarim 4:9) issues a command to remember specifically "the day" of Matan Torah.
Who are the two "Ishim" mentioned in the Pasuk?
Ramban: It refers to the Zekeinim who accompanied Moshe on to Har Sinai for the first Luchos, and to Yisrael as a whole, who stood at the foot of the mountain.
Oznayhim la'Torah: It refers to Aharon who accompanied Moshe part of the way when he ascended the mountain and to Yehoshua, who remained at the foot of the mountain awaiting Moshe's return, neither of whom were permitted on the mountain at all.
Why were the animals not permitted to graze in the vicinity of the mountain?
Ramban: The Isur of not touching the Mountain (even animals) was still in place, 1 and the Torah is now adding that the cattle should nor graze even in the vicinity of the mountain. This is because, whereas the first Luchos were given in honor of Yisrael, the second were due to the merit and the Tefilah of Moshe alone., and the Kavod that was revealed on this occasion was therefore greater than the first one. 2
What are the implications of the word "ha'Har ha'Hu"?
Rashi (in Ta'anis, 21b): 'As long as it retained its Kedushah, due to the Shechinah which rested on it, which it did even after Moshe brought down the second Luchos and beyond - until Rosh Chodesh Nisan, when Moshe set up the Mishkan. That is when the Shechinah moved from Har Sinai to the lid of the Aron, and that is when they were allowed to ascend Har Sinai once again.
