Exodus 34:27-35

Then the LORD said to Moses, “Write down these words, because with these words I have made an agreement with you and Israel.” Moses stayed there with the LORD forty days and forty nights, and during that time he did not eat food or drink water. And Moses wrote the words of the Agreement—the Ten Commandments—on the stone tablets. Then Moses came down from Mount Sinai, carrying the two stone tablets of the Agreement in his hands. But he did not know that his face was shining because he had talked with the LORD. When Aaron and all the people of Israel saw that Moses’ face was shining, they were afraid to go near him. But Moses called to them, so Aaron and all the leaders of the people returned to Moses, and he talked with them. After that, all the people of Israel came near him, and he gave them all the commands that the LORD had given him on Mount Sinai. When Moses finished speaking to the people, he put a covering over his face. Anytime Moses went before the LORD to speak with him, Moses took off the covering until he came out. Then Moses would come out and tell the Israelites what the LORD had commanded. They would see that Moses’ face was shining. So he would cover his face again until the next time he went in to speak with the LORD.