2 Chronicles 15:9

Now those from all the tribes of Israel who gave their hearts to seek Yahweh, the God of Israel, followed them to Jerusalem, to sacrifice to Yahweh, the God of their fathers.

So Jehoshaphat lived in Jerusalem. Indeed, he returned and went out among the people from Beersheba to the hill country of Ephraim and caused them to return back to Yahweh, the God of their fathers.

“Now as for you, son of man, take for yourself one stick and write on it, ‘For Judah and for the sons of Israel, his companions’; then take another stick and write on it, ‘For Joseph, the stick of Ephraim and all the house of Israel, his companions.’