The Cases of Tayammum, Its Conditions, and Repeating the Prayer

Question:
Finally, Honorable Shaykh, this questioner, Abu Hamd, says: What are the cases in which one resorts to tayammum, and what are its conditions? And if one performs tayammum, Honorable Shaykh, while water is available, what is required of him regarding repeating the prayer?

Answer:
Tayammum is a substitute for water in two cases: when water is not found , and in the case of illness where one is unable to perform wudu with water. In these two cases—when water is absent, or when one is unable to use water despite its presence—one performs tayammum with dust. If someone performs tayammum without one of these two causes, meaning he must repeat the prayer, he should perform wudu and repeat the prayer. For example, if he performs tayammum while water is available and he is able to use it, he must repeat the prayer. Yes.