2 Kings 15:5 - Joseph Benson’s Commentary on the Old and New Testaments

The Lord smote the king, so that he was a leper The cause of this stroke is related at large, 2 Chronicles 26:16-21. And dwelt in a several house Separated from conversation with others by virtue of the law, recorded Leviticus 13:46, which, being the law of the King of kings, bound kings no less than subjects. The Jews, by the term several house, understand a house in the country; where he might have liberty to take his pleasure, but not to meddle with public affairs. Jotham, the king's son, was over the house, &c. That is, he lived in the palace, and managed all the affairs of the court and of the kingdom, governing in his father's name as his vicegerent. It was in the twenty-seventh year of Azariah's reign that he was smitten with the leprosy, and he continued a leper twenty-five years, during which time Jotham administered the government, his father being incapable of it.