And the LORD came down upon mount Sinai, on the top of the mount: and the LORD called Moses up to the top of the mount; and Moses went up.
All Commentaries on Exodus 19:20 Go To Exodus 19
Bede
AD 735
Moses alone ascended to its very top, where the divine majesty shone forth in fire and a dark cloud. Only the more perfect know how to grasp and observe the deeper and most secret mysteries of the law; the carnalminded people, content with the external aspects of the letter, and gathered apart, as it were, and below, stood to hear the words from heaven.