Bible Notes Online - Numbers 26 - ESV
Commentary

v2-4: The second census. The people counted in 1.2-4 had all now died.

Such a list seems strange to many modern readers. However, culturally, it was important to belong to a community. And such genealogies and lists help to provide that. 'What these lists do is to maintain people's sense of identity and history as a community.' (David Devenish, Demolishing Strongholds)

v9-10: Dathan and Abiram were true Israelites, since their genealogy was known. Yet they had rebelled against God. They became a sign for those who would rebel against authority that was God-appointed and God-anointed.

v11: Yet the line of Korah was preserved, such was God's grace, that He did not slay the righteous people in that family with the unrighteous rebels.

v14: The tribe of Simeon were much reduced, possibly because of the rebellion of ch 25. Later, Simeon was unable to inherit its allotment with Canaan, because it was too large, and the tribe was effectively swallowed up into Judah's inheritance. In Deut 33, when Moses blessed the tribes, Simeon was not even mentioned.

v5-50: The total numbers were:

Reuben, 43,730; Simeon, 22,200; Gad, 40,500; Judah, 76,500; Issachar, 64,300; Zebulun, 60,500; Ephraim, son of Joseph, 32,500; Manasseh, son of Joseph, 52,700; Benjamin, 45,600; Dan, 64,400; Asher, 53,400; Naphtali, 45,400. The overall total, 601,730, was quite similar to that at the beginning of the period of wanderings.

v53-56: Moses spoke again of the inheritance in Canaan. There was no doubt that they would inherit the land. Also, their inheritance was properly in Canaan, not outside it.

v61: As in v9-10, the writer draws our attention to the rebels in the camp. We are to take warning, and watch our own hearts.