en_tn/1ch/21/02.md

count the people of Israel ... that I may know their number

It is apparent from 1 Chronicles 21:5 that David wanted to count only the men who were able to fight.

from Beersheba to Dan

The Israelites considered these two cities their most southern and most northern cities. David uses these cities to refer to all of Israel. (See: rc://en/ta/man/jit/figs-merism)