The Prophet ﷺ said, "Pure earth is the means of purification for the Muslim, even for ten years. But when you find water, let it touch your skin, for that is better."
عن النبي ﷺ قال: الصعيد الطيب وضوء المسلم ولو إلى عشر سنين؛ فإذا وجدت الماء فأمسه جلدك؛ فإن ذلك خير.
Abu Dawud (332) and Tirmidhi (124) both narrated it from the hadith of Khalid Haddan, and Nasai (322) from the hadith of Ayub, both of them, meaning Khalid and Ayub, from Abu Qilaba, from Amr bin Bujdan, from Abu Dharr, mentioning it in this abbreviated form. The detailed version is what Abu Dawud mentioned. Abu Dharr said, some sheep were gathered for the Messenger of Allah, so he said, "Abu Dharr, go out and tend them in the desert." So I went out to Rabaza, and janaba would afflict me, and I would remain in that state on Thursday and Saturday. Then I came to the Prophet, and he said, "Abu Dharr," but I remained silent. He said, "May your mother lose you, Abu Dharr, woe to your mother!" Then he called for me a black slave girl, who brought a large bowl containing water, and I had myself screened with a garment, and I concealed myself behind the mount and washed, and it was as though a mountain had been lifted off me. Then the Messenger of Allah said, "The clean earth..." and so on, and he mentioned the hadith.Abu Dawud said, the version of Amr bin Awn, who is one of Abu Dawud's own teachers, is more complete. Tirmidhi said, hasan sahih.I say, in the chain is Amr bin Bujdan, who narrated from Abu Dharr Ghifari and Abu Zayd Ansari, and from him narrated Abu Qilaba. Ali bin Madini said, no one narrated from him except him. So his status is unknown, except that Ajli said, "A Basran successor, trustworthy," in Tarikh Thiqat (p. 362). Ibn Hibban also deemed him trustworthy and included his hadith in his Sahih (1311), and Hakim in Mustadrak (1/176) said, a sahih hadith.Ibn Qattan discussed him in his book Wahm wal-Iham (3/no. 1073), saying, "This is undoubtedly a daif hadith," and he elaborated at length. Dhahabi said in Mizan (3/247), Tirmidhi graded it hasan, but did not raise it to the level of sahih because of the unknown status of Amr. End of quote. Hafiz said in Talkhis (1/154), Ajli did deem him trustworthy, and Ibn Qattan overlooked this when he said he was unknown, yet in Taqrib he said his status is not known, which is a contradiction.Abu Dawud also narrated it from the hadith of Hammad bin Salama, from Ayub, from Abu Qilaba, from a man of Banu Amir, who said, I entered into Islam, and my religious duties concerned me, so I came to Abu Dharr. Abu Dharr said, I found Madinah's climate disagreeable, so the Messenger of Allah ordered for me some camels and sheep, and said to me, "Drink from their milk," and Hammad said, and I think he also said, "and from their urine." Abu Dharr said, so I would go far from water while my family was with me, and he mentioned the rest.Abu Dawud said, Hammad bin Zayd narrated it from Ayub without mentioning "their urine." Abu Dawud said, this is not sahih, and regarding their urine there is nothing except the hadith of Anas, which the people of Basra alone transmitted. End of quote.Taqi Din inclined toward regarding it as sahih in Imam, saying, "It is strange that Ibn Qattan is not satisfied with Tirmidhi's grading as sufficient to establish the status of Amr bin Bujdan, despite his being the sole transmitter of the hadith, and this is a quotation of his own words, this is a hasan sahih hadith. What difference is there between saying he is trustworthy, and grading as sahih a hadith that he alone transmitted?"In summary, it is a hasan hadith, and it is the best thing available on this topic.