Abu Dharr (RA) narrated that: AlIah's Messenger (ﷺ) said: "Pure clean earth is a purifier for the Muslim; even if he did not find water for ten years. Then if he finds water, then let him use it (for purification) on his skin. For, that is better."
(Jami` at-Tirmidhi 124, Vol. 1, Book 1, Hadith 124)