Albert Barnes Commentary 2 Chronicles 19:4

"And Jehoshaphat dwelt at Jerusalem: and he went out again among the people from Beer-sheba to the hill-country of Ephraim, and brought them back unto Jehovah, the God of their fathers." — 2 Chronicles 19:4 (ASV)

Jehoshaphat, while declining to renounce the alliance with Israel (Compare to 2 Kings 3:7), was careful to show that he had no sympathy with idolatry and was determined to keep his people, so far as he possibly could, free from it. He therefore personally set about a second reformation, passing through the whole land from the extreme south to the extreme north (2 Chronicles 13:19).