Albert Barnes Commentary 2 Kings 5:1

"Now Naaman, captain of the host of the king of Syria, was a great man with his master, and honorable, because by him Jehovah had given victory unto Syria: he was also a mighty man of valor, [but he was] a leper." — 2 Kings 5:1 (ASV)

By him the Lord had given deliverance to Syria—An Assyrian monarch had pushed his conquests as far as Syria at this exact time, bringing all the kings of these regions into subjection. But Syria revolted after a few years and once more made itself independent. It was probably in this war of independence that Naaman had distinguished himself.

But he was a leper—leprosy came in various kinds and degrees (see Leviticus 13; Leviticus 14). Some of the lighter forms would not incapacitate a man from discharging the duties of a courtier and warrior.