What does 2 Kings 5:17 mean?

So Naaman said, 'If you won't take anything, please let me take as much dirt as two mules can carry, because from now on, I won't offer sacrifices or burnt offerings to any god except the Lord.' 2 Kings 5:17 - Modern Text Bible

(Naaman asks for some earth from Israel, wanting to worship the Lord alone from now on. He wants a physical reminder of where he met the true God.)