Exodus 34:28-35

Moses remained there on the mountain with the LORD forty days and forty nights. In all that time he ate no bread and drank no water. And the LORD wrote the terms of the covenant—the Ten Commandments—on the stone tablets. When Moses came down Mount Sinai carrying the two stone tablets inscribed with the terms of the covenant, he wasn’t aware that his face had become radiant because he had spoken to the LORD. So when Aaron and the people of Israel saw the radiance of Moses’ face, they were afraid to come near him. But Moses called out to them and asked Aaron and all the leaders of the community to come over, and he talked with them. Then all the people of Israel approached him, and Moses gave them all the instructions the LORD had given him on Mount Sinai. When Moses finished speaking with them, he covered his face with a veil. But whenever he went into the Tent of Meeting to speak with the LORD, he would remove the veil until he came out again. Then he would give the people whatever instructions the LORD had given him, and the people of Israel would see the radiant glow of his face. So he would put the veil over his face until he returned to speak with the LORD.