It should seem that the great design of the numbering of Israel was, with a view to impress upon the minds of the people the unalterable decrees of GOD. The LORD had sworn, that of all those men which had seen his glory, and his miracles, both in Egypt and in the wilderness, none of them should see the land of promise, because of their murmuring. And now, by the numbering the people, the vacancies found by death afforded proof of the divine veracity. See Numbers 14:21-24.
Related Commentaries of Numbers 26:1
Numbers 26:1-2
1 And it came to pass after the plague, that the LORD spake unto Moses and unto Eleazar the son of Aaron the priest, saying,
2 Take the sum of all the congregation of the children of Israel, from twenty years old and upward, throughout their fathers' house, all that are able to go to war in Israel.