וַיֹּאמְרוּ, אֶל־מֹשֶׁה, דַּבֵּר־אַתָּה עִמָּנוּ, וְנִשְׁמָעָה; וְאַל־יְדַבֵּר עִמָּנוּ אֱלֹהִים, פֶּן־נָמוּת. וַיֹּאמֶר מֹשֶׁה אֶל־הָעָם, אַל־תִּירָאוּ, כִּי לְבַעֲבוּר נַסּוֹת אֶתְכֶם, בָּא הָאֱלֹהִים; וּבַעֲבוּר, תִּהְיֶה יִרְאָתוֹ עַל־פְּנֵיכֶם־לְבִלְתִּי תֶחֱטָאוּ. שמות כ׃טו־טז
And they said to Moshe: 'You speak with us, and we will hear; but don't let God speak with us, lest we die.' And Moses said unto the people: 'Fear not; for God is come to uplift you, so that that His fear on your faces, that you will not sin.'
It is odd to see this exchange and not wonder what's going on. The clearest simplest way to understand it is that this experience of at the giving of the Torah was so powerful that the people were afraid that the experience was going to overpower them and kill them. Considering that Am Yisrael has just seen that Hashem has the power to do anything at all (evidenced by the plagues and the splitting of the sea), and the fact that Hashem has just told Am Yisrael that they would be his nation, it is difficult to think that Hashem would now subject them to an experience that would kill them.
Moshe's response is also odd. If the point is for them to be afraid, then why is Moshe telling them not to be afraid?
A better explation of these verses confirms a feeling that I have had about this episode for a while. It seemed to me that the opening that allowed all of our sins in the midbar (and since the midbar) was due to the fact that we felt we could not listen to all of what Hashem wanted to say to us at Har Sinai.
It appears to me that Am Yisrael fully understood that Hashem intended for
them to survive the giving of the Torah. They were afraid of a different death.
They were afraid that if they heard the whole Torah directly from Hashem that when in the future they would sin, there would be no remaining opening for mercy, and they would die of their sin. Moshe's response is to counter this fear. He explains to them that they should not fear that this experience will leave them vulnerable to death if they sin, because Hashem has come to give them such a penetrating fear of Him that it would be impossible for them to sin in the first place.