דברי הימים ב, פרק כ״ו, פסוק י״ט

A tense standoff reaches its breaking point within the sacred walls of the Temple. The king, accompanied by a small entourage, faces a large and determined group of priests who have come to force him out [ביאור שטיינזלץ]. Met with their resistance, the king reacts with intense anger [מצודת ציון, רלב״ג, מצודת דוד]. This rage is mixed with a deep sense of sadness and a broken spirit, an emotional response that surfaces when a person's will is thwarted [מלבי״ם].

Standing right next to the incense altar [מצודת דוד, ביאור שטיינזלץ], the king is already holding a censer filled with incense and prepared for burning [מצודת ציון, מצודת דוד, רד״ק, ביאור שטיינזלץ]. Fueled by his fury, he intends to use the censer as a weapon to strike the priest who is standing before him and blocking his path [רש״י]. However, at the exact moment his anger flares against the priests, God strikes him [רלב״ג].

Suddenly, a bright, white mark of leprosy breaks out on his forehead. The affliction is described as shining because of its brilliant white color, making it appear to glow like the sun [מצודת דוד, חומת אנך]. The appearance of the leprosy specifically on the forehead carries deep significance. The impurity emerges from this exact spot to serve as a visible sign of the king's wicked thoughts [מלבי״ם]. Furthermore, the punishment operates on the principle of measure for measure. Because the king attempted to force his way into a holy place that did not belong to him, God punishes him with an affliction that results in his complete rejection, forcing his removal even from the royal spaces that rightfully belong to him [חומת אנך]. Struck by this sudden and shocking condition, the king is compelled to flee the Temple immediately [רלב״ג].