But when he was strong, his heart was lifted up to his destruction: for he transgressed against the LORD his God, and went into the temple of the LORD to burn incense upon the altar of incense. And Azariah the priest went in after him, and with him fourscore priests of the LORD, that were valiant men: and they withstood Uzziah the king, and said unto him, “It appertaineth not unto thee, Uzziah, to burn incense unto the LORD, but to the priests the sons of Aaron, that are consecrated to burn incense: go out of the sanctuary; for thou hast trespassed; neither shall it be for thine honour from the LORD God.”
Then Uzziah was wroth, and had a censer in his hand to burn incense: and while he was wroth with the priests, the leprosy even rose up in his forehead before the priests in the house of the LORD, from beside the incense altar. And Azariah the chief priest, and all the priests, looked upon him, and, behold, he was leprous in his forehead, and they thrust him out from thence; yea, himself hasted also to go out, because the LORD had smitten him. And Uzziah the king was a leper unto the day of his death, and dwelt in a several house, being a leper; for he was cut off from the house of the LORD: and Jotham his son was over the king’s house, judging the people of the land.
Now the rest of the acts of Uzziah, first and last, did Isaiah the prophet, the son of Amoz, write. So Uzziah slept with his fathers, and they buried him with his fathers in the field of the burial which belonged to the kings; for they said, “He is a leper:” and Jotham his son reigned in his stead. 2 Chronicles 26:16-23
Further reading: 2 Chronicles 26; Numbers 16; Deuteronomy 8:14-17; Matthew 10:18, 28; Galatians 2:11