Exodus 34:29-31

When Moses came down from Mount Sinai with the two tablets of the Testimony in his hand, he did not know that the skin of his face was shining [with a unique radiance] because he had been speaking with God. When Aaron and all the Israelites saw Moses, behold, the skin of his face shone, and they were afraid to approach him. But Moses called to them, and Aaron and all the leaders of the congregation returned to him; and he spoke to them.