What does 2 Chronicles 20:2 mean?

Some people came and told Jehoshaphat, 'A huge army is coming against you from Edom, from the other side of the Dead Sea. They’re already at Hazazon Tamar (that’s En Gedi).','commentary':'Jehoshaphat receives urgent news that enemy forces are already close, putting his kingdom in immediate danger.'} , 2 Chronicles 20:2 - Modern Text Bible

(Jehoshaphat is alarmed and decides to ask God for help. He calls everyone in Judah to fast and seek God together.)