2 Kings 5:14-15

14So he went down and dipped himself in the Jordan seven times, as the man of God had told him, and his flesh was restored and became clean like that of a young boy.

15Then Naaman and all his attendants went back to the man of God. He stood before him and said, “Now I know that there is no God in all the world except in Israel. So please accept a gift from your servant.”