Musnad Ahmad 648:22

Ya'la ibn 'Ubayd narrated to us, al-A'mash narrated to us, from Shaqiq, who said: I was sitting with 'Abdullah and Abu Musa. Abu Musa said: "O Abu 'Abd al-Rahman, if a man becomes ritually impure (junub) and does not find water, should he pray?" He said: "No." He said: "Did you not hear the statement of 'Ammar to 'Umar: 'The Messenger of Allah (ﷺ) sent me and you, and I became ritually impure, so I rolled in the soil. Then we came to the Messenger of Allah (ﷺ) and informed him, and he said: "It would have been sufficient for you to do like this," and he wiped his face and his hands once.'" He said: "I did not see 'Umar convinced by that." He said: "How then do you deal with this verse: {And if you do not find water, then seek clean soil} [An-Nisa: 43]?" He said: "If we were to grant them a concession in this, one of them, when he found cold water, would wipe himself with the soil." Al-A'mash said: I said to Shaqiq: "So he only disliked it for this reason?"