Musnad Ahmad 648:17

'Affan narrated to us, 'Abd al-Wahid narrated to us, Sulayman al-A'mash narrated to us, Shaqiq narrated, saying: I was sitting with 'Abdullah and Abu Musa al-Ash'ari. Abu Musa said to 'Abdullah: "If a man does not find water, should he not pray?" 'Abdullah said: "No." Abu Musa said: "Do you not remember when 'Ammar said to 'Umar: 'Do you not remember when the Messenger of Allah (ﷺ) sent me and you for some camels, and I became in a state of major ritual impurity (janabah), so I rolled in the dust? When I returned to the Messenger of Allah (ﷺ), I informed him, and the Messenger of Allah (ﷺ) laughed and said: "It would have been sufficient for you to say like this," and he struck his palms against the ground, then wiped his palms together, and wiped his face with one wiping in one strike?'" 'Abdullah said: "Indeed, I did not see 'Umar convinced by that." Abu Musa said to him: "Then what about this verse in Surat an-Nisa: {And you do not find water, then perform tayammum with pure soil} [an-Nisa: 43]?" He (the narrator) said: 'Abdullah did not know what to say, and he said: "If we were to grant them a concession in tayammum, it would be likely that one of them, if the water felt cold on his skin, would perform tayammum." 'Affan said: Yahya—meaning Ibn Sa'id—denied it. So I asked Hafs ibn Ghiyath, and he said: "Al-A'mash used to narrate it to us from Salamah ibn Kuhayl," and he mentioned Abu Wa'il.