Is the scarcity of water after searching a necessary condition for the validity of Tayammum?

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The absence of water after searching is unanimously required for the validity of Tayammum. This is established by the Almighty's statement, "And if you find no water, then seek clean earth" (Quran 5:6), and the Prophet's saying, "The earth is sufficient for you as long as you do not find water." Since Tayammum is a purification necessitated by need and does not remove ritual impurity (hadath), it is only permissible when necessity dictates. When water is present, necessity is absent.