Exodus 34:29-33

29Now when Moses came down from Mount Sinai with the two tablets of the testimony in his hand – when he came down from the mountain, Moses did not know that the skin of his face shone while he talked with him.

30When Aaron and all the Israelites saw Moses, the skin of his face shone; and they were afraid to approach him.

31But Moses called to them, so Aaron and all the leaders of the community came back to him, and Moses spoke to them.

32After this all the Israelites approached, and he commanded them all that the Lord had spoken to him on Mount Sinai.

33When Moses finished speaking with them, he would put a veil on his face.