2. Mose 13:21

From Etham, at the edge of the desert which separates Egypt from Asia, the Israelites were to enter the pathless desert, and leave the inhabited country. Jehovah then undertook to direct the march, and give them a safe-conduct, through a miraculous token of His presence. Whilst it is stated in Exo 13:17, Exo 13:18, that Elohim led them and determined the direction of their road, to show that they did not take the course, which they pursued, upon their own judgment, but by the direction of God; in Exo 13:21, Exo 13:22, it is said that "Jehovah went before them by day in a pillar of cloud, to lead them the way, and by night in a pillar of fire, to give them light, to go by day and night," i.e., that they might march at all hours. (Note: Knobel is quite wrong in affirming, that according to the primary work, the cloud was first instituted after the erection of the tabernacle. For in the passages cited in proof of this (Exo 40:34.; Num 9:15., Exo 10:11-12, cf. Exo 17:7), the cloud is invariably referred to, with the definite article, as something already known, so that all these passages refer to Exo 13:21 of the present chapter.) To this sign of the divine presence and guidance there was a natural analogon in the caravan fire, which consisted of small iron vessels or grates, with wood fires burning in them, fastened at the end of long poles, and carried as a guide in front of caravans, and, according to Curtius (de gestis Alex. M. V. 2, 7), in trackless countries in the front of armies also, and by which the direction of the road was indicated in the day-time by the smoke, and at night by the light of the fire. There was a still closer analogy in the custom of the ancient Persians, as described by Curtius (iii. 3, 9), of carrying fire, "which they called sacred and eternal…

In this chapter we have, I. The commands God gave to Israel, 1. To sanctify all their firstborn to him (Exo 13:1, Exo 13:2). 2. To be sure to remember their deliverance out of Egypt (Exo 13:3, Exo 13:4), and, in remembrance of it, to keep the feast of unleavened bread (Exo 13:5-7). 3. To transmit the knowledge of it with all possible care to their children (Exo 13:8-10). 4. To set apart unto God the firstlings of their cattle (Exo 13:11-13), and to explain that also to their children (Exo 13:14-16). II. The care God took of Israel, when he had brought them out of Egypt. I. Choosing their way for them (Exo 13:17, Exo 13:18). 2. Guiding them in the way (Exo 13:20-22). And III. Their care of Joseph's bones (Exo 13:19).

13:21 The pillar of cloud and the pillar of fire were to be the Israelites’ constant companions for the next forty years.