Charles Ellicott Commentary 2 Kings 5:27

"The leprosy therefore of Naaman shall cleave unto thee, and unto thy seed for ever. And he went out from his presence a leper [as white] as snow." — 2 Kings 5:27 (ASV)

Shall cleave. —Or, cleave! That is, let it cleave. The prophetic sentence is naturally expressed as an imperative.

A leper as white as snow. —Compare Exodus 4:6 and Numbers 12:10. A sudden outbreak of leprosy may result from extreme fright or mortification (Michaelis).

To your seed forever. —Like other skin diseases, leprosy is hereditary. If it is thought that the sentence is too strong, it should be remembered that the prophet is really pronouncing inspired judgment on the sin of Gehazi, and milder language might have produced erroneous impressions. Covetousness and lying are never spared in Scripture, and it is well for humankind that it is so. (Compare Acts 5)