Easton's Bible Dictionary (1897)
A valley in the west of Judah, near Mareshah; the scene of Asa’s conflict with Zerah the Ethiopian (2 Chr. 14:9-13). Identified with the Wady Safieh.
Smith's Bible Dictionary (1863)
(watch-tower), The valley of, the spot in which Asa joined battle with Zerah the Ethiopian. (2 Chronicles 14:10) only.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
ZEPH'ATHAH (watch-tower), VALLEY OF, near Mareshah. 2 Chr 14:10. A deep valley is found near the site of Mareshah, running down to Beit Jibriu (Eleutheropolis), and thence into the plain of Philistia, which Porter identified with Zepliathah. See Mareshah.