"And when Moses had finished speaking with them, he put a veil over his face"

    "And he was there with the Lord forty days and forty nights; he ate no bread and drank no water; and he wrote down on the tablets the terms of the covenant, the Ten Commandments.

      So Moses came down from Mount Sinai. And as Moses came down from the mountain bearing the two tablets of the Pact, Moses was not aware that the skin of his face was radiant, since he had spoken with Him. Aaron and all the Israelites saw that the skin of Moses' face was radiant; and they shrank from coming near him. But Moses called to them, and Aaron and all the chieftains in the assembly returned to him, and Moses spoke to them. Afterward all the Israelites came near, and he instructed them concerning all that the Lord had imparted to him on 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 leave the veil off until he  came out; and when he came out and told the Israelites what he had been commanded, the Israelites would see how radiant the skin of Moses' face was. Moses would then put the veil back over his face until he went in to speak with Him".

Exodus 34,  28-35

(JPS Tanakh)