Achor in Easton's Bible Dictionary
trouble, a valley near Jericho, so called in consequence of the trouble which the
sin of Achan caused Israel (Josh. 7:24,26). The expression "valley of Achor"
probably became proverbial for that which caused trouble, and when Isaiah (Isa.
65:10) refers to it he uses it in this sense: "The valley of Achor, a place for
herds to lie down in;" i.e., that which had been a source of calamity would become
a source of blessing. Hosea also (Hos. 2:15) uses the expression in the same sense:
"The valley of Achor for a door of hope;" i.e., trouble would be turned into joy,
despair into hope. This valley has been identified with the Wady Kelt.