2 Chronicles 20:33 Commentary - English Annotations on the Holy Bible by Matthew Poole

The high places where not taken away; not fully nor universally; of which See Poole "2Ch 17:6". The fault was not in Jehoshaphat, but in the people, who, though they did worship the true God, yet would not be confined to the temple, but for their own conveniency, or from their affection to their ancient custom, chose to worship him in the high places; which Jehoshaphat was forced to connive at, lest those people, being debarred from that dearly-beloved practice, should fall into a neglect of God and his worship.