Numbers 26:2

“Take the sum of all the congregation of the children of Israel, etc.] Excepting the Levites, who were to be numbered by themselves, and at a different age; this sum was to be taken, that it might appear that all of the old generation that came out of Egypt, of the age at which this sum was taken, were now dead, excepting two, as the Lord had threatened; and partly that as they were now about to enter the land of Canaan, it might be divided to them according to their number; as well as to show the faithfulness of God to his word and promise, that he would multiply and make them fruitful, notwithstanding all their provoking sins and transgressions: from twenty years old and upwards, throughout…”

“Take the sum of all the congregation--The design of this new census, after a lapse of thirty-eight years, was primarily to establish the vast multiplication of the posterity of Abraham in spite of the severe judgments inflicted upon them; secondarily, it was to preserve the distinction of families and to make arrangements, preparatory to an entrance into the promised land, for the distribution of the country according to the relative population of the tribes.”

“Take the sum - They were numbered twice before, Exo 30:11-12; Num 1:1-2. Now they are numbered a third time, to demonstrate the faithfulness of God, both in cutting all those off whom he had threatened to cut off, Num 14:29, and in a stupendous increase of the people according to his promise, notwithstanding all their sins, and the sweeping judgments inflicted upon them; and to prepare the way for the equal division of the land, which they were now going to possess. Numbers 26:7”

“The plague having swept away the last of that devoted generation, which provoked the Lord to "swear in his wrath that they should not enter" Canaan; he now, after an interval of 38 years, commands another census of the Israelites to be made, to preserve the distinction of families, and to regulate the tribes previous to their entry into the promised land, as well as to ascertain the proportion of land which should be allotted to each tribe. For, though the whole was divided by lot, yet the portions were so disposed, that a numerous tribe did not draw where the lots assigned small inheritances, or the contrary. Num 1:2, Num 1:3; Exo 30:12, Exo 38:25, Exo 38:26 Numbers 26:3”