Does a wall become pure if it dries by the wind? And does clothing become impure if it touches the dry wall while slightly wet, or if the clothing is dry, or if one doubts the dryness of either, or the place of istijmar?

A wall that has become impure can only be purified by washing it with pure water. Drying it does not purify it, according to most scholars. If the wall is dry and the garment is wet and they touch, the affected area of the garment becomes impure. However, if both are dry, the garment does not become impure. Doubt about whether one of them is dry or whether the area touched an impure spot does not necessitate the impurity of the garment, because the default state of things is purity. Wiping with a wall for purification (istijmar) is not sufficient if it is painted with a smooth coating that is unsuitable for removing impurities, based on Al-Nawawi's statement: "And in the meaning of a stone is every solid, pure, and impurity-removing substance," and Al-Shirbini's explanation: "Excluded by 'impurity-removing' are things like glass and smooth reeds." Furthermore, using walls for istijmar is prohibited according to most scholars.