Exodus 34:27-29

27And Jehovah said to Moses, Write thee these words; for after the tenor of these words have I made a covenant with thee and with Israel.

28— And he was there with Jehovah forty days and forty nights; he ate no bread, and drank no water. — And he wrote on the tables the words of the covenant, the ten words.

29And it came to pass, when Moses came down from mount Sinai — and the two tables of testimony were in Moses' hand, when he came down from the mountain — that Moses knew not that the skin of his face shone through his talking with him.