וַיַּ֨רְא אַהֲרֹ֜ן וְכָל־בְּנֵ֤י יִשְׂרָאֵל֙ אֶת־מֹשֶׁ֔ה וְהִנֵּ֥ה קָרַ֖ן ע֣וֹר פָּנָ֑יו וַיִּֽירְא֖וּ מִגֶּ֥שֶׁת אֵלָֽיו׃
И когда Аарон и все дети Израиля увидели Моисея, вот, кожа его лица послала лучи; и они боялись приблизиться к нему.
Sifrei Bamidbar
"Outside of the camp shall you send them": What is the intent of this (after "They shall send out of the camp")? From "They shall send out of the camp," I might think the intent is (only) that they not touch the ark or its bearers, but they should be assigned a place for themselves (inside the camp). It is, therefore, written "Outside of the camp shall you send them": "and they shall not make unclean their camps" — whence (i.e., from the three-fold repetition of "camp") they stated: There were three camps: the Israelite camp, the Levite camp, and the camp of the Shechinah. From the entrance to Jerusalem until the Temple mount — the Israelite camp. From the entrance to the Temple mount until the azarah (the Temple courtyard) — the Levite camp. From the entrance to the azarah and inwards — the camp of the Shechinah. (Ibid. 3) "in whose midst I dwell": Beloved are Israel, who, even when they are tamei, the Shechinah is among them, as it is written (Vayikra 16:16) "who dwells with them in the midst of their uncleanliness," and (Bamidbar) 35:34) "And you shall not defile the land which you inhabit, in which I dwell, for I, the L-rd, dwell in the midst of the children of Israel (even when they are unclean)."
Sifrei Bamidbar
(Ibid. 5:4) "And the children of Israel did so, and they sent them outside the camp": R. Yossi Haglili says: Come and see how great is the power of transgression. For before they stretched forth their hands to transgress (with the golden calf), there were no zavim or lepers among them, and after they did so, there were zavim and lepers among them. In the course (of our learning) we learned that these three things (zavim, lepers, and tamei meth) occurred on the same day (the day that they made the golden calf). R. Shimon b. Yochai says: Come and see how great is the power of transgression. For before they stretched forth their hands to transgress, what is written of them? (Shemot 24:17) "and the sight of the glory of the L-rd was like a consuming fire on the top of the mountain in the eyes of the children of Israel" — They did not fear and they did not tremble. After they stretched forth their hands to transgress, what is written of them? (Ibid. 34:30) "And Aaron and all of Israel saw Moses, and, behold, the skin of his face shone, and they were afraid to approach him." "And the children of Israel did so": This is to declare the praise of Israel, that just as Moses told them, thus did they do. What is the intent of (the additional) "As the L-rd spoke to Moses, so did the children of Israel do"? To teach that the unclean ones themselves, (who were sent out), did not protest.
Midrash Tanchuma
Our teachers maintained that in reward for three things Moses was granted three things. As a reward for And Moses hid his face (Exod. 3:6), he was granted The skin of his face sent forth beams (ibid. 34:30); as a reward for For He feared (ibid. 3:6), he was granted They were afraid to come nigh unto him (ibid. 34:30); and as a reward for He was afraid to look (ibid. 3:6), he was granted The similitude of the Lord doth he behold (Num. 12:18).