The answer is: Forehead

2 Chronicles 26:19 - Uzziah was struck with leprosy on his forehead when he unlawfully entered the temple to burn incense.

King Uzziah’s story presents a fascinating intersection of ambition, divine authority, and the stark limitations of human power. After he chose to enter the temple, an act strictly reserved for the priests, he was swiftly met with consequences—his forehead was afflicted with leprosy. It's noteworthy that leprosy in ancient times was not only a physical ailment; it symbolized spiritual and social separation. Thus, this condition commanded a deep recognition of Uzziah's transgressions both before God and his people.

Interesting trivia: Uzziah, also called Azariah, was initially an extraordinary king of Judah known for military successes and establishing a strong economy. This flourishing reign highlights how quickly one's downfall can stem from arrogance. His leprosy was a life sentence that rendered him unclean, isolating him during a time when communal identity and physical presence were greatly valued—cast out from the very society he had once led.

Moreover, what Uzziah’s situation echoes is similar to another biblical story involving King Saul, who also fell significantly from grace due to his disobedience to God’s commands. In both cases, a focus on honors led to a heart-felt necktie from divine purposes.

Leprosy often symbolizes our own follies or conditions we harbor in secrecy, reflecting on how vital it is to maintain humility and recognize the rightful order of authority in both earthy and heavenly realms. Hence, King Uzziah's leprosy functions as a striking reminder of the importance of staying within one’s divinely ordained boundaries.