Divrey Hayamim Bais 20:1-3

Orthodox Jewish Bible

20 It came to pass after this also, that the Bnei Moav, and the Bnei Ammon, and with them some Ammonim, came against Yehoshaphat to make milchamah.

² Then there came some that told Yehoshaphat, saying, There cometh a great multitude against thee from beyond the Yam (Dead Sea), from Aram; and, hinei, they are in Chatzatzon-Tamar, which is Ein-Gedi.

³ And Yehoshaphat feared, and set his face to inquire of Hashem, and proclaimed a tzom throughout all Yehudah.