The literal sense of the Word is called a cloud, because the internal sense, which is called glory, cannot be comprehended by a person unless he is spiritually regenerated and thence enlightened. The internal sense of the Word, or divine truth in its own glory, if it should appear before a person who is not regenerated, would be like a thick darkness in which he could see nothing at all.

(Odkazy: Arcana Coelestia 8106)