Exodus 34:28-35

So he was there with the LORD forty days and forty nights. He neither ate bread nor drank water. And he wrote on the tablets the words of the covenant, the Ten Commandments. When Moses came down from Mount Sinai, with the two tablets of the testimony in his hand as he came down from the mountain, Moses did not know that the skin of his face shone because he had been talking with God. Aaron and all the people of Israel saw Moses, and behold, the skin of his face shone, and they were afraid to come near him. But Moses called to them, and Aaron and all the leaders of the congregation returned to him, and Moses talked with them. Afterward all the people of Israel came near, and he commanded them all that the LORD had spoken with him in Mount Sinai. And when Moses had finished speaking with them, he put a veil over his face. Whenever Moses went in before the LORD to speak with him, he would remove the veil, until he came out. And when he came out and told the people of Israel what he was commanded, the people of Israel would see the face of Moses, that the skin of Moses’ face was shining. And Moses would put the veil over his face again, until he went in to speak with him.