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.