Charles Ellicott Commentary 2 Samuel 8:13

"And David gat him a name when he returned from smiting the Syrians in the Valley of Salt, even eighteen thousand men." — 2 Samuel 8:13 (ASV)

When he returned from smiting the Syrians. —Possibly, from the similarity in the original between Syria and Edom (see 2 Samuel 8:3; 2 Samuel 8:12), the words “he smote Edom” have dropped out of the text, but this supposition is not necessary. The course of affairs appears to have been as follows: the war was originally undertaken against the Ammonites (2 Samuel 10:1–12), who had obtained the aid of the Syrians. In the first campaign their combined armies were defeated (2 Samuel 10:13–14), and they sought aid from every quarter, from the tribes beyond the Euphrates, on the north (2 Samuel 10:16), and from the Edomites on the south.

David first inflicted a crushing defeat upon the allies near Hamath, and then “returned” to the south, where he again met them in “the valley of salt”—the Arabalt south of the Dead Sea. This latter army was naturally composed chiefly of Edomites, and is so called in 1 Chronicles 18:12 and in the title of Psalm 60:0, but is here spoken of as Syrians because the whole confederacy is called by the name of its most powerful member.

David himself returned from the southern campaign; but what was done by his general, Abishai, under his orders, is naturally said to have been done by him. Meanwhile, when this first battle, attended with the slaughter of 18,000 men, had been won by Abishai, Joab, the general-in-chief, being set free by the victories in the north, gained another battle in the same locality, killing 12,000 (Psalms 60:0 (title)). The power of Edom was now completely broken. The whole forces of Israel were then mustered under Joab to overrun their country and destroy all its male inhabitants (1 Kings 11:15–16)—certain of them, however, excepted (1 Kings 11:17). Their descendants in later ages were relentless foes of Israel. (Compare the prophecy of Isaac in Genesis 27:40.)

In this summary of David’s reign, the historian here turns from his wars and victories over other nations to the internal affairs of his kingdom. Substantially the same list of officers is again given in 2 Samuel 20:23–26.