The Cloud, the pillar of cloud
Archimandrite Nikifor’s Biblical Encyclopedia
(Ex. 13:21). When the Israelites went out of Egypt with Pharaoh’s permission and entered the wilderness of Arabia, the LORD went before them by day in a pillar of cloud, showing them the way. By day the pillar resembled a dark, heavy cloud, and by night a bright and flaming one, like fire. Some think that there were two clouds: one to overshadow them, and the other to light the way. It also served as a sign for halting and for setting out again on the march (Num. 9:17-23). The cloud served as the customary symbol of the presence of God among His people.
It often rested over the mercy seat of the Ark of the Covenant, or filled the Tabernacle of the congregation. When Isaiah beheld in vision the glory of God in His temple, the house was filled with smoke, or a thick cloud (Is. 6:4). When God the Father testified concerning His Son on the mount of the Transfiguration, “a bright cloud overshadowed them” (Matt. 17:5). The prophet Isaiah foretells the presence of God in the Church for all