Easton's Bible Dictionary
A place where it is said David smote the Syrians (2 Sam. 8:13). This valley (the’ Arabah) is between Judah and Edom on the south of the Dead Sea. Hence some interpreters would insert the words, “and he smote Edom,” after the words, “Syrians” in the above text. It is conjectured that while David was leading his army against the Ammonites and Syrians, the Edomites invaded the south of Judah, and that David sent Joab or Abishai against them, who drove them back and finally subdued Edom. (Comp. title to Ps. 60.) Here also Amaziah “slew of Edom ten thousand men” (2 Kings 14:7; comp. 8: 20-22 and 2 Chr. 25:5-11).
International Standard Bible Encyclopedia (ISBE)
<p>(ge' ha-melach): The scene of battles, firstly, between David or his lieutenant Abishai and the Edomites (2Sa 8:13; 1Ch 18:12; Ps 60, title), and later between Amaziah and these same foes (2Ki 14:7; 2Ch 25:11). It is tempting to connect this "Valley of Salt" with es Sebkhah, the marshy, salt-impregnated plain which extends from the southern end of the Dead Sea to the foot of the cliffs, but in its present condition it is an almost impossible place for a battle of any sort. The ground is so soft and spongy that a wide detour around the edges has to be made by those wishing to get from one side to the other. It is, too, highly probable that in earlier times the whole of this low-lying area was covered by the waters of the Dead Sea. It is far more natural to identify ge' ha-melach with the Wady el-Milch ("Valley of Salt"), one of the three valleys which unite at Beersheba to form the Wady ec-Ceba`. These valleys, el-Milch and ec-Ceba, together make a natural frontier to Canaan.</p><p>E. W. G. Masterman</p>