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." (Using translation from Ibn Mājah 569)
عَمَّارٌ بْنُ يَاسِرٍ يَا أَمِيرَ الْمُؤْمِنِينَ أَتَذْكُرُ إِذْ أَنَا وَأَنْتَ فِي سَرِيَّةٍ فَأَجْنَبْنَا فَلَمْ نَجِدْ المَاءً فَأَمَّا أَنْتَ فَلَمْ تُصَلِّ وَأَمَّا أَنَا فَتَمَعَّكْتُ بالتُّرَابِ فصَلَّيْتُ فَأَتَيْنَا النبي ﷺ فذَكَرْنَا ذَلِكَ لَهُ فَقَالَ «إِنَّمَا كَانَ يَكْفِيكَ» وَضَرَبَ يَدَيْهِ إِلَى الْأَرْضِ ثُمَّ نَفَخَ فَمَسَحَ بِهِمَا وَجْهَهُ وَكَفَّيْهِ شَكَّ سَلَمَةُ فلَا أَدْرِي فِيهِ إِلَى الْمِرْفَقَيْنِ أَوْ إِلَى الْكَفَّيْنِ فقَالَ عُمَرُ نُوَلِّيكَ مِنْ ذَلِكَ مَا تَوَلَّيْتَ