A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
num 26:1ISRAEL NUMBERED. (Num. 26:1-51)
after the plague--That terrible visitation had swept away the remnant of the old generation, to whom God sware in His wrath that they should not enter Canaan (Psa 95:11).
num 26:2Take 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.
num 26:7These are the families of the Reubenites--the principal households, which were subdivided into numerous smaller families. Reuben had suffered great diminution by Korah's conspiracy and other outbreaks [Num 16:1].
num 26:10the earth opened her mouth, and swallowed them up together with Korah--rather, "the things of Korah." (See on Num 16:35; compare Psa 106:17).
num 26:11Notwithstanding the children of Korah died not--Either they were not parties to their father's crime, or they withdrew from it by timely repentance. His descendants became famous in the time of David, and are often mentioned in the Psalms [Psa 42:1; Psa 44:1; Psa 45:1; Psa 46:1; Psa 47:1; Psa 48:1; Psa 49:1; Psa 84:1; Psa 85:1; Psa 87:1; Psa 88:1], also in Ch1 6:22, Ch1 6:38.
num 26:12The sons of Simeon--It is supposed that this tribe had been pre-eminent in the guilt of Baal-peor and had consequently been greatly reduced in numbers.
Thus God's justice and holiness, as well as His truth and faithfulness, were strikingly displayed: His justice and holiness in the sweeping judgments that reduced the ranks of some tribes; and His truth and faithfulness in the extraordinary increase of others so that the posterity of Israel continued a numerous people.
num 26:53the land shall be divided according to the number of names--The portion of each tribe was to be greater or less, according to its populousness.
num 26:54To many thou shalt give the more inheritance--that is, to the more numerous tribes a larger allotment shall be granted.
according to those that were numbered--the number of persons twenty years old at the time of the census being made, without taking into account either the increase of those who might have attained that age, when the land should be actually distributed, or the diminution from that amount, occasioned during the war of invasion.
num 26:55the land shall be divided by lot--The appeal to the lot did not place the matter beyond the control of God; for it is at His disposal (Pro 16:33), and He has fixed to all the bounds of their habitation. The manner in which the lot was taken has not been recorded. But it is evident that the lot was cast for determining the section of the country in which each tribe should be located--not the quantity of their possessions. In other words, when the lot had decided that a particular tribe was to be settled in the north or the south, the east or the west, the extent of territory was allocated according to the rule (Num 26:54).
num 26:58families of the Levites--The census of this tribe was taken separately, and on a different principle from the rest. (See Exo 6:16-19).
num 26:62twenty and three thousand--so that there was an increase of a thousand (Num 3:39).
males from a month old and upward--(See on Num 3:14).
num 26:64among these there was not a man . . . numbered . . . in the wilderness of Sinai--The statement in this verse must not be considered absolute. For, besides Caleb and Joshua, there were alive at this time Eleazar and Ithamar, and in all probability a considerable number of Levites, who had no participation in the popular defections in the wilderness. The tribe of Levi, having neither sent a spy into Canaan, nor being included in the enumeration at Sinai, must be regarded as not coming within the range of the fatal sentence; and therefore it would exhibit a spectacle not to be witnessed in the other tribes of many in their ranks above sixty years of age.
Tribes Chap. 1 Chap. 26 Increase Decrease
Reuben 46,500 43,730 -- 2,770
Simeon 59,300 22,200 -- 37,100
Gad 45,650 40,500 -- 5,150
Judah 74,600 76,500 1,900 --
Issachar 54,400 64,300 9,900 --
Zebulun 57,400 60,500 3,100 --
Ephraim 40,500 32,500 -- 8,000
Manasseh 32,200 52,700 20,500 --
Benjamin 35,400 45,600 10,200 --
Dan 62,700 64,400 1,700 --
Asher 41,500 53,400 11,900 --
Naphtali 53,400 45,400 -- 8,000
Total 603,550 601,730 59,200 61,020
Total decrease 1,820