Luke 9:34

The cloud was undoubtedly the shekinah, the visible vehicle for God’s localized presence during the wilderness wanderings (Exodus 13:21-22; Exodus 16:10; Exodus 24:16; Exodus 40:34-38). It would also accompany the Son of Man’s coming (Isaiah 4:5; Daniel 7:13). Its presence is another indication that the Second Coming is in view. The Greek word episkiazo ("overshadow," also in Luke 9:34 but translated "enveloped" in the NIV) translates the Hebrew word shakan in the Septuagint from which the term "shekinah" comes. Thus the reader has two hints that God was drawing near: the bright (Gr. photeine) cloud and its overshadowing (Gr. episkiazo). Evidently the cloud enshrouded Jesus, Moses, and Elijah, and the disciples became fearful (cf. Matthew 17:5-7).