'Be Clean' in the Bible

Elisha sent a messenger to him, saying, "Go and wash in the Jordan seven times, and your flesh shall come again to you, and you shall be clean."

Aren't Abanah and Pharpar, the rivers of Damascus, better than all the waters of Israel? Couldn't I wash in them, and be clean?" So he turned and went away in a rage.

His servants came near, and spoke to him, and said, "My father, if the prophet had asked you do some great thing, wouldn't you have done it? How much rather then, when he says to you, 'Wash, and be clean?'"