2 Chronicles 26:19, commentary and pictures

Only the descendants of Aaron were authorized to serve as priests, so Uzziah's entering the sanctuary to burn incense was an unauthorized and arrogant seizure of priestly work upon himself. When the priests opposed him with united protest and correction, he became filled with wrath and stood in rebellious anger against them because he, the king, had been rebuked. While he stood wrathful in the house of the Lord with a censer in his hand to burn incense beside the incense altar, leprosy suddenly rose up on his forehead before the priests as a divine judgment that did not permit him to profane the sanctuary.

In dismay he fled the temple and never again entered its courts, being forced to leave the temple to live in isolation. Even though he was king acting as ruler, when afflicted he had to give up the scepter and surrender his royal duties and leave society. He remained a leper until his death some years later, so his presumptuous sin marred the closing years of his reign and brought the judgment of Heaven upon himself. Neither his exalted rank and position nor his long life of service could excuse his violation of God's plain command.

Leprosy was regarded among the Jews as a judgment for sin and as a symbol of sin, incurable and deadly, rendering its sufferer unclean and cut off from the community. The verse stands as a living example of the folly of departing from a plain Thus saith the Lord and warns against presumptuous disobedience, showing that anger at correction does not prevent divine judgment.