2 Kings 5:13-15

Then his servants approached and said to him, “My father, if the prophet had told you to do some great thing, would you not have done it? How much more then, when he has said to you, ‘Wash, and be clean?’ ” So he went down and plunged himself into the Jordan seven times, just as the man of God had said; and his flesh was restored like that of a little child and he was clean. Then Naaman returned to the man of God, he and all the people in his group, and stood before him. He said, “Behold, I know that there is no God in all the earth, except in Israel; so now accept a blessing and gift from your servant.”