What did Moshe mean when he told the people that Hashem has come "l'Va'avur Nasos Eschem"?
Rashi (citing the Mechilta): He meant that Hashem came to raise Yisrael's esteem in the eyes of the nations 1 by virtue of the fact that He spoke to them directly. 2
Ramban #1: What he meant was that by appearing to Yisrael directly, and revealing the Shechinah to them, He got them accustomed 3 to Emunah, injecting it into their hearts, to cleave to Him forever.
Ramban #2 (citing Moreh Nevuchim): The revelation was to prepare Yisrael for future tests - inasmuch as, should a false prophet come to negate what they had heard, having seen the Emes with their own eyes, they will be able to overrule his claims.
Ramban #3: He meant literally, that Hashem was coming to test them, 4 as to whether they would now keep all His Mitzvos, having driven all doubts out of their minds - to see whether they really loved Him and wanted Him and His Mitzvos. 5
Rashbam: He meant that Hashem appeared to them directly in order to rebuke them.
Seforno: He meant that Hashem appeared to Yisrael Panim el Panim 6 with His celestial retinue, in order to accustom them to prophecy
Moshav Zekenim: He means that Hashem was testing them with ten voices, each one stronger than the previous one - and they stood firm through all of them, even though their spirit departed with each one.
Rashi: As in Yeshayah 62:10, 49:22.
A privilege that no other nation has ever merited.
Ramban: As in Shmuel I 17:39.
Ramban: As in Shmuel I 17:39. Since this Pasuk can be understood in two ways.
Ramban: Since a master will test his servant's loyalty in one of two ways; sometimes he will test him by placing upon him a heavy workload - testing him by the way he undertakes to handle it; and sometimes He is particularly nice to him, to see whether he acknowledges what he did for him by working harder and showing him more respect, as was the case here (Refer to 20:17:1:1** - See Ramban).
Seforno: As He did with Eliyahu ha'Navi. See Melachim I 19:13).
What did Moshe mean when he added "u'Va'avur Tih'yeh Yir'aso Al Peneichem ... "?
Rashi and Ramban #1: he meant that, when Yisrael saw Hashem in His awe, they knew that there was none other besides Him and they would fear him (and refrain from sinning).
Ramban #2: He meant that the fear of the fire that they were seeing would prevent them from sinning.
Nedarim 20a: He was referring to a sense of bashfulness which leads to Yir'as Hashem (and through which they merited 1 prophets - Moshav Zekenim). 2
Seforno: It is referring to the fear that gripped them after seeing the visions that they saw on Har Sinai. 3
Mesilas Yesharim (Perek 24): The primary fear is that a person is always trembling, even when he does not see a pitfall, his heart is worried lest a pitfall is in front of him, and he is not careful of it. Through such fear, one does not come to sin, and if he does, it is like an Oneis.
Yevamos 79a: 'This nation has three characteristics; they are compassionate, bashful (reserved) and kindhearted. Bashful - because the Torah writes "u'Va'avur Tih'yeh Yir'aso Al Peneichem."
Moshav Zekenim citing R. Yehudah ha'Chasid: What was the merit? They said, "if we continue to hear Hashem's voice, we will die" (Devarim 5:22)! The merit was, they did not impose on Hashem to speak softly, rather, they trusted Moshe.
Moshav Zekenim (citing R. Yehudah ha'Chasid): Although there were prophets who prophesied not on account of this merit (Shem, Ever, the Avos, Bil'am and Iyov)! Through this, they merited famous prophets who prophesied even about other nations - Yirmeyah, Yeshayah and Yechezkel. Even though Bil'am prophesied about the Keini, Ashur and Mo'av, this was by himself. Hashem sent prophets only from Yisrael.
Seforno: Like the story cited in Chulin 9a, of R. Yehoshua, who said to the Emperor of Rome 'If you cannot look at the sun, which is only one of the courtiers that serve before Ha'Kadosh-Baruch-Hu, how can you expext to see Ha'Kadosh-Baruch-Hu Himself?'
What is the meaning of the final phrase "u'Va'avur Tih'yeh Yir'aso Al Peneichem, l'Vilti Secheta'u"?
Nedarim 20a #1 (according to the Tana Kama): Refer to 20:17:2:5. This teaches us that bashfulness leads to fear of sin.
Nedarim 20a #2 (according to R. Meir): Whoever does not possess (a touch of) bashfulness, we know that his ancestors were not at Har Sinai. 1
Which explains why David ha'Melech rejected the Giv'onim when they came to join Yisrael following a display of a lack of all three Midos. See Torah Temimah, note 100, citing the Yerushalmi in Kidushin, 4:1
How would Hashem's revelation result in Yir'as Shamayim?
Rashi and Ramban #1: By witnessing the awe of Hashem, they would realize that there is none like Him, and therefore fear Him.
Ramban #2: Fear of the great fire that they were seeing would prevent them from sinning.
Seforno: Seeing the Shechinah would plant the fear of Hashem in their hearts and prevent them sinning. 1
Seforno: As R. Yehoshua said to the Emperor of Rome (See Chulin 60a) 'If you say that you cannot look at the sun, which is merely one of Hashem's creations, how much more so can you not look at the Shechinah itself!'
