2 Chronicles 20:2-3

Then it was reported to Jehoshaphat, “A great multitude has come against you from beyond the [Dead] Sea, out of Aram (Syria); and behold, they are in Hazazon-tamar (that is, Engedi).” Then Jehoshaphat was afraid and set himself [determinedly, as his vital need] to seek the LORD; and he proclaimed a fast throughout all Judah.