Numbers 26:4

4 "Take a census of those 20 years old and above as the LORD commanded Moses." The Israelites who left the land of Egypt were:

Numbers 26:4 Meaning and Commentary

Numbers 26:4

[Take the sum of the people], from twenty years old and upward,
&c.] At the same age at which the sum was taken before, ( Numbers 1:3 ) so that there could not be one that was more than sixty years of age, of all those that went into the land of Canaan, except Joshua and Caleb, and besides some few in the tribe of Levi, which did not come into either of these musters:

and the Lord commanded Moses, and the children of Israel, which went
forth out of the land of Egypt;
as Moses had a command to number the people before, so he had now. The sin of David was, that he numbered the people when he had no command for it; Moses, when he brought the people out of Egypt, had them committed to him by number; and now being about to die, he delivers them up as it were by number again, as Jarchi observes.

Numbers 26:4 In-Context

2 Take a census of the entire Israelite community, from 20 years old and above by their households, to determine everyone in Israel who is eligible for military service.

3 Moses and Eleazar the priest spoke to the people on the plains of Moab by the Jordan opposite Jericho:

4 "Take a census of those 20 years old and above as the LORD commanded Moses." The Israelites who left the land of Egypt were:

5 Reuben, Israel's oldest son. Reuben's descendants: from Hanoch, the Hanochite clan; from Pallu, the Palluite clan;

6 from Hezron, the Hezronite clan; from Carmi, the Carmite clan.