The answer is: Leprosy

2 Ki 5:1

Naaman's ailment, leprosy, was a significant condition in the ancient world. Often regarded much more seriously than we do today, he was essentially an outcast because of this debilitating skin disease. Not only did leprosy affect one's physical connections, but it also implicated spiritual beliefs—people thought such afflictions were often punishments or tests of faith.

Interestingly, while the term "leprosy" covers a broad spectrum of skin conditions today, ancient records show that it was often characterized by a range of signs—some more severe than others. Biblical leprosy generally meant becoming unclean, requiring strict protocols and separating individuals from society. It’s intriguing to note that Naaman, although a commander, could swiftly lose his status amongst his people because of his condition.

The story of Naaman doesn’t just deal with physical healing—it explores wider themes of pride and humility. As Naaman braves the trip to Israel seeking a cure, he initially struggles with the simplicity of the solution prescribed by the prophet Elisha. The double-dipping in the Jordan might sound like a trivial task to us, but it signifies a powerful point about surrendering to divine wisdom, even when it feels frustratingly simple or beneath oneself.

In an interesting echo back to purity and separation, the lepers during Jesus’ time, notably the ten healed in Luke 17, serve as a reminder of how far—or ineffectively—societal structures can remove individuals from community and grace. Both stories show how healing often starts with humility and a willingness to follow through on promises made by God through faith.