Perform tayammum if there is no access to water for ablution before prayer .

This hadith explains how to perform ablution when no water is available. It was narrated by 'Abdur Rahman bin Abza and 'Ammar bin Yasir, who both reported that a man came to Umar bin Al-Khattab and said he became junub but no water was available. Ammar then reminded Umar of a time they were on a journey together, where Umar did not pray but Ammar rolled himself on the ground and prayed. He then informed the Prophet about it, who said it would have been sufficient for him to do so. The Prophet then demonstrated what he meant by stroking lightly the earth with his hands, blowing off the dust, and passing his hands over his face and hands. This hadith teaches us that if we are in a situation where there is no access to water for ablution before prayer, we can use dust or sand instead as an alternative form of purification known as tayammum.