He spread a cloud for a covering. The "pillar of the cloud" is intended. It was a "covering" to the Israelites on the night of the passage of the Red Sea (Exodus 14:19, Exodus 14:20), and perhaps also to some extent in the wilderness, when it may have sheltered them from the sun's rays (Hengstenberg); but its main purpose was to direct them on their way (Exodus 14:21), to tell them when to move and when to step, and how long to stop (Exodus 40:36-38).
And fire to give light in the night. By night the "pillar of the cloud" became a "pillar of fire," shedding a certain radiance around, and giving the people under all circumstances sufficient light (Exodus 13:21; Exodus 40:38).