Exodus 13:21 - Arthur Peake's Commentary on the Bible

Exodus 13:21 f. J. The Guiding Pillar. Faith in the Divine guidance (cf. Exodus 13:17 * E) is by J expressed in symbolic form. On a wilderness journey everyone needs a guide. By night and day the unsleeping keeper of Israel leads them with His pillar of fiery cloud. E, who connects guidance with the angel of God (Exodus 14:19 a), also tells of a pillar of cloud (Exodus 33:9 f., etc.) which descends to the door of the sacred tent, as the sacramental sign and pledge of Yahweh's approach to speak with Moses. In P the fiery cloud that had shrouded Sinai, the mount of vision (Exodus 24:15-18 a), rests on the completed Tabernacle (Exodus 40:34-38), and its rising is the signal for resuming the march. That God's people should achieve faith in God's presence with them as Guide, Revealer, and Protector was the essential thing. Under what specific aspect and through what particular symbol they expressed their faith at different times it is less important to know. Possibly some practice, like the carrying of a brazier with its smoke and flame at the head of a Greek or Persian army or Arab caravan, was the outward and visible source of the symbolic expressions. Gressmann picturesquely compares the appearance of Vesuvius in eruption in 1905, furnishing a landmark by day and night with its smoke and fire. Presumably he believes Mt. Sinai to have been an active volcano on the horizon (cf. next paragraph).