"The Messenger of Allah ﷺ said: 'Clean earth is the Wudu' of the Muslim, even if he does not find water for ten years.'" (Using translation from Nasāʾī 322)  

قَالَ رَسُولُ اللهِ ﷺ «الصَّعِيدُ الطَّيِّبُ وَضُوءُ الْمُسْلِمِ وَإِنْ لَمْ يَجِدِ الْمَاءَ عَشَرَ سِنِينَ»