Sa'id bin Abd al-Rahman bin Abza narrates from his father that a man came to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) and said: If I become junub and do not find water, what should I do? Sayyiduna Ammar bin Yasir (may Allah be pleased with him) said to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him): Do you not remember that we were on a journey, and you and I became junub? You did not pray, while I rolled about in the dust and then prayed. I came to the Prophet (peace and blessings be upon him) and told the Prophet (peace and blessings be upon him) about it, and the Prophet (peace and blessings be upon him) said: "It would have sufficed you to do like this." Then the Prophet (peace and blessings be upon him) struck the ground with his palms, blew into them, and then wiped his face and his palms.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 1004