Things on which Tayammum is allowed
692. Tayammum can be done on earth, sand, lump of clay or stone but the recommended precaution is that if earth is available tayammum should not be performed on anything else. If earth is not available, then it can be performed on sand or a lump of clay, and in absence of these on a stone.
693. Tayammum can also be done on gypsum or lime-stone. Similarly, tayammum is allowed on dust which gathers on the dress or the carpets etc., provided that its quantity is such that it can be termed as soft earth. However, it is a recommended precaution, that using dust be avoided if other alternatives are available. It is also a recommended precaution that baked gypsum, lime, brick and mineral stones be avoided.
694. If a person cannot find earth, sand, lump of clay or stone, he should perform tayammum on mud, and if even that is not available, then on dust particles which settle on the carpets or the dresses, though it may not be in a quantity which could be considered as soft earth. And if none of these things is available he should, on the basis of recommended precaution, pray without tayammum, but it will be obligatory for him to repeat the prayers later as Qadha.
695. If a person can gather some earth by shaking the carpet etc. then to do tayammum with dust particles will not be correct. And similarly if he can make mud dry and obtain earth from it, then tayammum on wet mud will be incorrect and void.
696. If a person does not have water, but has snow or ice he should, if possible, melt it into water and perform Wudhu and Ghusl. And if it is not possible to do so and also he does not have anything on which tayammum is allowed then it is necessary that he should give Qadha after Namaz time. But it is better that he should make the parts of Wudhu or Ghusl wet with snow or ice. And if even this is not possible he should perform tayammum on snow or ice and offer prayers in time.
697. If a thing like straw, on which tayammum is void, gets mixed with clay and sand, then tayammum cannot be performed on it. However, if it is so little that it gets lost in the sand or clay, then tayammum with it is valid.
698. If a person does not own anything on which to perform tayammum he should, if possible, get it by purchasing or other similar means.
699. Performing tayammum on mud wall is valid but the recommended precaution is that if dry earth or clay is available, tayammum should not be performed on wet earth or mud.
700. The thing on which a person performs tayammum should be Pak and, if he has no Pak thing on which tayammum would be correct, it is not obligatory for him to offer prayers. He should, however, give its Qadha, though it is better that he should pray within the prescribed time.
701. If a person was sure that tayammum on a particular thing was valid and he did it accordingly, but came to know later that tayammum performed was void, he would repeat the prayers performed with that tayammum.
702. The thing used for tayammum should not have been usurped, or obtained without the owner's permission. Tayammum on usurped objects like earth, etc, will be void.
703. Tayammum performed in usurped area or space is not void. Hence, if a person strikes his hands on the earth for tayammum in his own property, and then enters the property of another person without obtaining permission to wipe his hands on his forehead, his tayammum is correct and valid, though he has committed a sin (by trespassing).
704. If someone does tayammum on a usurped object, forgetfully or by way of negligence, his tayammum will be valid. However, if a person himself usurps something, and then forgets that he has usurped it, then tayammum performed on such a thing cannot be considered as valid.
705. If a person is imprisoned in a usurped place and both the water and earth of that place are usurped, he should pray with tayammum.
706. The thing on which a person is performing tayammum should, if possible, on the basis of obligatory precaution, have particles which would stick to the hands, and after striking hands on it, one should not shake off all the particles from ones hands.
707. It is Makrooh to perform tayammum on the earth of a pit, and street dust, or the saline earth, on which a layer of salt has not settled. If, however, a layer of salt has settled on the earth, performance of tayammum on it is void.