Perform wudhu from that which has been touched by fire.

This hadith is about the importance of performing wudu, which is a ritual washing performed by Muslims before prayer. According to the Prophet Muhammad, it is important to use water that has been heated by fire when performing wudu. This could be done in various ways such as boiling water on a stove or heating it up in a pot over an open flame. By using heated water, one can ensure that their body and clothing are properly cleansed for prayer. Additionally, this hadith teaches us the importance of following Islamic teachings and rituals even if they may seem small or insignificant at first glance.