2 Samuel 24:5

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 them, not knowing what was the design of all this Aroer was a city given to the tribe of Gad, and rebuilt by them, Numbers 32:34;

on the right side of the city; that is, of Aroer, the south side of it, as the Targum, did Joab and his army pitch:

that [lieth] in the midst of the river of Gad; which was the river Arnon, so called now from the tribe of Gad, which possessed it, and so the Targum, in the midst of the river of the tribe of Gad; for in the midst of the river Arnon Aroer lay, see Joshua 13:9;

and toward Jazer; another city given to the Gadites, Numbers 32:3; and, according to Bunting u, was sixteen miles from Aroer.

u Travels, c. p. 147.