Perform tayamumm when there is no access to water

This hadith discusses the Islamic practice of ablution before prayer. If one does not have access to water, they can perform an alternative form of ablution called tayammum. This involves using clean sand or dust instead of water for purification. The hadith also mentions a disagreement between Umar and Ammar about this practice. Umar was not satisfied with Ammar's statement on the matter, although it is still permissible to perform tayammum if no water is available. This hadith teaches us that we should always strive for purity before prayer and that we should respect other people's opinions even if we do not agree with them completely.