2 Chronicles 16:7

GOD'S PROPHET REBUKED ASA; AND ASA WAS ANGRY

"And at that time Hanani the seer came to Asa king of Judah, and said unto him, Because thou hast relied on the king of Syria, and hast not relied on Jehovah thy God, therefore is the host of the king of Syria escaped out of thy hand. Were not the Ethiopians and the Lubim a huge host, with chariots and horsemen exceeding many? yet, because thou didst rely on Jehovah, he delivered them into thy hand. For the eyes of Jehovah run to and fro throughout the whole earth, to show himself strong in the behalf of them whose heart is perfect before him. Herein thou hast done foolishly; for from henceforth thou shalt have wars. Then Asa was wroth with the seer, and put him in the prison-house; for he was in a rage with him because of this thing. And Asa oppressed some of the people at the same time."

One thing that the Chronicler most certainly had in mind here was to show the colossal failure of the whole institution of the monarchy. Even a good king like Asa could not remain uncorrupted while wielding the scepter of unchallenged power. The constant pressure of the flattering sycophants that surround every ruler, and the constantly nourished and promoted conceit of any natural man have the power eventually to break down the strongest heart.

Also, it may have been his way of establishing the principle that all men are sinners. The Sinless One did not appear until the Christ was cradled in the manger at Bethlehem.