When Azariah the chief priest and all the priests turned to him and saw his leprous forehead, they rushed him out. Indeed, he himself hurried to get out, because the LORD had afflicted him.
Here is the only blot we find on the name of king Uzziah, and it is such a one as lies not on any other of the kings. Whoredom, murder, oppression, persecution, and especially idolatry, gave characters to the bad kings and some of them blemishes to the good ones, David himself not excepted, witness the matter of Uriah.
Commenting on 2 Chronicles 26:16-23
Now the rest of the acts of Uzziah, first and last,.... What were done by him, both in the beginning and latter end of his reign: did Isaiah the prophet, the son of Amoz, write: not in his own prophecy, but in the history of his own times, which was usual for every prophet to write, though now lost, see Kg2 15:6.
Because the Lord had smitten him - "Because the Word of the Lord had brought the plague upon him." - T.