It came about when Moses was coming down from Mount Sinai (and the two tablets of the testimony were in Moses' hand as he was coming down from the mountain), that Moses did not know that the skin of his face shone because of his speaking with Him.
(New American Standard Bible)
And it came to pass, when Moses came down from mount Sinai with the two tables of testimony in Moses' hand, when he came down from the mount, that Moses wist not that the skin of his face shone while he talked with him.
(King James Version)