11:1 when kings go out to battle. See 1 Kin. 20:22, 26. In the Near East, springtime was a logical time for military campaigns, since the winter rains would have ceased and the labor-intensive harvest would not have begun.
David sent Joab. This is not the first time that David has sent Joab on a military expedition (10:7), but since it was the time when “kings go out to battle” and yet “David remained at Jerusalem,” there may be some criticism of David for remaining behind.
besieged Rabbah. Called “Rabbah of the Ammonites” in Deut. 3:11 and elsewhere (12:26; 17:27; Jer. 49:2; Ezek. 21:20), this city was the capital of Ammon (Amos 1:13–15). It is twenty-four miles east of the Jordan River opposite Jericho. In New Testament times it was called Philadelphia, and today it is Amman, Jordan. See also 10:14 and note.