For the tent of Yahweh, which Moses made in the wilderness, and the altar of burnt offering, were at that time in the high place at Gibeon.
"The major reason for taking a census in Israel was to lay the basis for levying taxes (Exodus 30:12; Numbers 3:40-51) or registering men for military service (Numbers 26:1-4)." [Note: Thompson, p. 160. Cf. 21:4-7.] 