Jamieson, Fausset and Brown on 2 Chronicles 32:27-29

27-29. he had exceeding much riches and honour--(compare 2Ki 20:13; Is 39:2). A great portion of his personal wealth, like that of David and Uzziah, consisted in immense possessions of agricultural and pastoral produce. Besides, he had accumulated large treasures in gold, silver, and precious things, which he had taken as spoils from the Philistines, and which he had received as presents from neighboring states, among which he was held in great honor as a king under the special protection of Heaven. Much of his great wealth he expended in improving his capital, erecting forts, and promoting the internal benefit of his kingdom.