What does 2 Kings 5:12 mean?

'Aren't the rivers in Damascus better than any river in Israel? Couldn't I just wash in them and be clean?' So he turned and stormed off, furious. 2 Kings 5:12 - Modern Text Bible

(Naaman thinks the rivers back home are better and feels insulted by the simplicity of Elisha's instructions. He almost misses out because of his pride.)