Ver. 3. When ye see the ark—and the priests the Levites bearing it— See Numbers 4:15. The Levites of the family of Kohath were appointed to the office of carrying the ark of the covenant; but, in extraordinary cases, this care was committed to the priests, who are here called the Levites, for a reason given in a former place. See Deuteronomy 17:9.
Then ye shall remove, &c.— Whereas in common marches the ark was carried in the middle of the camps, as we read Numbers 2:17. God on this occasion would have it carried in the front, or at the head of the whole army, as it had been at the first march which was made on leaving mount Sinai. Numbers 10:33.