Clouds as transporting and concealing
to show God's physical presence, the Shekinah cloud of Glory (cf. Exod. 13:21; 14:19,20,24; 16:10; 19:9; Num. 11:25; Neh. 9:19)
to cover His Holiness so that man would not see Him and die (cf. Exod. 33:20; Isa. 6:5)
to transport Deity (cf. Ps. 18:9; 104:3; Isa. 19:1; Dan. 7:13; Nah. 1:3; Acts 1:9,11; 1 Thess. 4:17)
The cloud often serves to transport God and, at the same time, it serves to conceal his glory from human gaze. This is evident in the transfiguration narratives and in the presence of God speaking with Moses on the mountain.
The biblical writers see clouds as God’s swift chariot (cf. also Ps. 18:9; 104:3; Isa. 19:1; Dan. 7:13; Nah. 1:3; 1 Thess. 4:17). If we stop to reflect on this, we can imagine that people who never had the opportunity to fly in an airplane as it passed near or through clouds might easily be persuaded that clouds appear quite substantial and easily able to transport their passengers.
When meeting with Moses on Mount Sinai, God uses a cloud not only to transport himself but also to hide himself from Moses, lest he see his face and die (Exod 33:19-20). The assumption here is that God uses a cloud to travel from his throne in heaven to Mount Sinai. Cloaked in the same cloud, God hides his face. This is the Shekinah, the cloud of Glory (cf. Exod. 13:21; 14:19,20,24; 16:10; 19:9; Num. 11:25; Neh. 9:19).