Exodus 13:21

And the LORD went before them by day in a pillar of a cloud, to lead them the way; and by night in a pillar of fire, to give them light; to go by day and night:

And the Lord went before them,.... Who is called the Angel of the Lord, Exodus 14:19, not a created but the uncreated Angel, the Angel of Jehovah's presence, in whom his name, nature, and perfections were, even the Word and Son of God, the Lord Christ, see 1 Corinthians 10:9 who went before the armies of Israel, as their King, Leader, and Commander:

by day in a pillar of a cloud, to lead them the way; through the Red sea, and the wilderness, at the edge of which they now were, which was untrodden, and trackless, and the way through it very difficult to find; and being a sandy desert, as soon as a path was made, it was immediately covered with sand, and to be seen no more: this cloud was not an ordinary one, but extraordinary, supernatural, and miraculous; in the superior part of it, it was in the form of a pillar, rising upwards towards heaven; in the lower part of it, it was more spread, and covered the camp of Israel; for, besides the use of it to show the way through a trackless wilderness, it was a shelter and protection from the scorching heat of the sun in a sandy desert, where there was scarce anything to screen them from it, to which the allusion is in Isaiah 4:5 this cloud was an emblem of Christ, who has sometimes appeared clothed with a cloud, Revelation 10:1 of the obscurity of his human nature, of the fulness of grace in him, and being in the form of a pillar, of his uprightness, firmness, stability, and visibility in it; and of the use and benefit he is to his people, partly to show them the way in which they should go, by his Spirit and word, and lead them in it by his own example, whom it becomes them to follow, he being a wise, safe, and constant guide; and partly to shelter and protect them from the heat of a fiery law, from the flaming sword of justice, from the wrath of God, from the fiery darts of Satan, and from the furious persecution of wicked men, sometimes compared to the violent heat of the sun, Song of Solomon 1:6

and by night in a pillar of fire, to give them light; whenever they travelled by night, as they sometimes did, and in those hot countries it was very agreeable; and this pillar of fire gave them light when the moon shone not, and was a direction to them which way to go: sometimes it is night with the people of God, a night of darkness and desertion, of drowsiness, sleepiness, and carnal security, or of affliction and distress: Christ is the light and comfort of his people, and by his Spirit and word illuminates, guides, and directs them what to do, and where and how to walk:

to go by day or night; to direct them in their journey, whether by night or day: this was but one pillar, though Aben Ezra thinks they were two; but it may be observed they are mentioned as one, and that the pillar of cloud in the night was a cloud of darkness to the Egyptians, and gave light to the Israelites, Exodus 14:19, see also Numbers 9:21 and it is easy to observe that what appears as a cloud or smoke in the daytime, looks like fire in the night: so when Alexander's army was on the march, as a signal,

"fire was observed in the night, and smoke by day,''

as says the historian {x}: nor can, this account of Moses seem incredible to the Heathens themselves, as Clemens of Alexandria observes {y}, since they relate a story somewhat similar to this, which they profess to believe; as, that when Thrasybulus brought the exile Grecians from Phyle, and willing to do it secretly, a pillar was his guide, and as he passed in the night through untrodden paths, when the moon shone not, and it was a dark winter night, a light was seen going before him, which brought them safe to Mynichia, and then left them: indeed this was not so extraordinary and miraculous, if true, as this pillar, as Bishop Patrick observes, because it was but for a night, whereas this continued all the forty years in the wilderness, until the Israelites came to Canaan's land, as follows: the Arabic geographer {z} speaks of exhalations arising out of caves at the sides of mountains, which in the daytime looked like smoke, and in the night time like fire.

{x} Curtius, l. 5. c. 2.
{y} Strom. l. 1. p. 348.
{z} Climat. 3. par. 8.