They crossed the Jordan and camped near Aroer, south of the town in the middle of the valley, and proceeded toward Gad and Jazer.
And they passed over Jordan,.... To take the number of the tribes of Reuben and Gad and the half tribe of Manasseh first: and pitched in Aroer; for it seems that Joab and the captains had the army with them, and the several captains under their command, partly to assist in numbering the people, and partly to keep them in awe, lest they should oppose...
they passed over Jordan--This census was taken first in the eastern parts of the Hebrew kingdom; and it would seem that Joab was accompanied by a military force, either to aid in this troublesome work, or to overawe the people who might display reluctance or opposition. the river of Gad--"Wady" would be a better term.
And pitched in Aroer - This was beyond Jordan, on the river Arnon, in the tribe of Gad: hence it appears, says Calmet, that they began their census with the most eastern parts of the country beyond Jordan.