Sunan Ibn Majah, 569

It was narrated from Sa'eed bin 'Abdur-Rahman bin Abza from his father, that:A man came to 'Umar bin khattab and said: "I became impure following sexual emission and cannot find any water." 'Umar said to him: "Do not pray." But 'Ammar bin Yasir said: "Do you not remember, O Commander of the Believers, when you and I were on a military expedition and we became sexually impure and could not find water? As for you, you did not pray, but I rolled in the dust and then prayed. When I came to the Prophet and told him what had happened, he said: 'It would have been enough for you (to do this).' (Then demonstrating) the Prophet struck the ground with his hands, then blew on hem, and wiped his face and palms with them

Rapporté par Sa’eed bin ‘Abdur-Rahman bin Abza, d’après son père : Un homme est venu voir ‘Umar bin Khattab et a dit : "Je suis devenu impur après un rapport sexuel et je ne trouve pas d’eau." ‘Umar lui a dit : "Ne prie pas." Mais ‘Ammar bin Yasir a dit : "Ne te souviens-tu pas, ô Commandeur des Croyants, quand toi et moi étions en expédition et que nous sommes devenus impurs sans trouver d’eau ? Toi, tu n’as pas prié, mais moi, je me suis roulé dans la poussière puis j’ai prié. Quand je l’ai raconté au Prophète, il a dit : 'Cela t’aurait suffi de faire ainsi.'" (Puis en montrant) le Prophète a frappé le sol avec ses mains, a soufflé dessus, puis a essuyé son visage et ses paumes