Tayammum should be performed instead of Wudhu or Ghusl in the following seven circumstances:
First: When it is not possible to procure sufficient water for performing Wudhu or Ghusl.
655. If a person happens to be in a populated area he should make his best efforts to procure water for Wudhu or Ghusl till such time that he loses all hope. And if he happens to be in a desert, he should search for water on the way or at nearby places. And if the land is uneven, or densely wooded, and it is difficult to walk, he should search for water in all the four directions for a distance covered by one or two flings of an arrow. (A fling is equal to about two hundred steps).
656. If out of the four directions, some are even and others are uneven, one should search for water in the even direction to the extent of two arrow flings, and on the side which is uneven to the extent of one arrow fling.
657. It is not obligatory for a person to search for water in the direction where he is sure that water is not available.
658. If the time left for Namaz is not short, and if he is sure or feels
sure that water is available at a farther place, he should go there to procure
water, provided that going there is not extremely difficult, and that the distance
is not unusually long. And if he has mere suspicion about water being there,
then it is not necessary for him to go.
In his commentary on the book entitled Man la Yahzuruhul Faqih the late Allama Majlisi has defined the distance covered by an arrow to be equal to 200 footsteps.
659. It is not necessary that a person should go himself in search of water. He can send a reliable person for this purpose. And it is sufficient if one person goes on behalf of many.
660. If a person feels that there might be some water in the provision he carries or at the place of encampment or even in the convoy, he should search for it thoroughly, till he is satisfied that there is no water or he becomes hopeless.
661. If a person searched for water before the time for Namaz, but did not find it and if he stayed there till the time of prayers set in, he should search for water again, as a recommended precaution, provided he feels that water may be found.
662. If a person searched for water after the time for Namaz had set in, and did not find it, if he stayed there till the time for next prayers, and if he felt there was a possibility of water being found, the recommended precaution is that he should go in search of water again.
663. When the time left for prayers is short or when there is fear of thieves or wild beasts or when the search for water is unbearable, it is not necessary for one to search for water.
664. If a person does not search for water till the time for Namaz approaches Qadha, in spite of the fact that he would have found water if he had tried, such a person has committed a sin, but the namaz which he will pray with tayammum will be valid.
665. If a person is sure that he cannot get water and does not, therefore, go in search of water and offers his prayers with tayammum, but realises after prayers that if he had made an effort he would have fetched water, he should, as an obligatory precaution, do wudhu and repeat the prayers.
666. If a person could not get water after a search and prayed with tayammum and then learns later after offering prayers that water was available at the place where he had searched, his prayers is valid.
667. If a person believed that the time left for prayers was little, and prayed with tayammum without going in search of water, but later learnt after the prayers but before the expiry of time that there was time for a search of water, then the obligatory precaution is that he should repeat that prayer.
668. If the time for Namaz has set in and a person is already with Wudhu, he should not allow his Wudhu to become void if he knows that he will not be able to find water or he will not be able to do Wudhu again. As an obligatory precaution, he should not invalidate his Wudhu deliberately. However, a man can have sex with his wife even if he knows that he will not be able to do Ghusl.
669. Similarly, if a person is with Wudhu before the time for prayers set in, and knew that if he made his Wudhu void, it would not be possible for him to get water, the recommended precaution is that he should try to keep his Wudhu intact. As an obligatory precaution, he should not invalidate the Wudhu deliberately.
670. If a person has just sufficient water for Wudhu or for Ghusl, and if he knows that if he spills it he will not be able to get water again, it is haraam for him to spill it if the time for prayers has already set in, and the obligatory precaution is that he should not throw it away even before the time for prayers sets in.
671. If a person knew that he would not get water, and yet made his Wudhu void or spilled it after the time for prayers had set in, he committed a sin but his prayers with tayammum will be order. However, the recommended precaution is that he should offer the Qadha of the prayers.
672. If a person is unable to procure water on account of old age or weakness, or fear of a thief or a beast, or because he does not possess means to draw water from a well, he should perform tayammum. The same would apply if acquiring water is intolerably difficult. But in this last situation, if a person, inspite of the difficulty, did not perform tayammum, and did Wudhu, his Wudhu will be valid.
673. If a bucket, a rope and other similar implements are needed for pulling water out of a well, and the person concerned is obliged to purchase or hire them, he should do so even if he has to pay much more than the usual rate. Similarly, he has to buy the water even if it is sold at a higher price. However, if by doing so, his economic condition is harmed, then it is not obligatory to procure them.
674. If a person is obliged to take a loan for procuring water he should take a loan. However, if he knows or feels that it will not be possible for him to repay the loan it is not obligatory for him to take a loan.
675. If digging a well does not involve much hardship the person concerned should dig a well to get water.
676. If he is given water by another person without any obligation he should accept it.
677. If a person fears that if he uses water his life will be endangered, or he will suffer from some ailment or physical defect, or the illness from which he is already suffering will be prolonged, or become acute or some complications may arise in its treatment, he should perform tayammum. However, if he can avoid the harm by using warm water, he should prepare warm water and do Wudhu, or Ghusl when it is necessary.
678. It is not necessary to be absolutely certain that water is harmful to him. If he feels that there is a probability of harm, and if that probability is justified by popular opinion, giving cause for some fear, then he should do tayammum.
679. If a person has an eye disease and water is harmful to him he should perform tayammum.
680. If a person performs tayammum on account of certainty or fear about water being harmful to him but realises before Namaz that it is not harmful, his tayammum is void. And if he realises this after having prayed he should offer the prayers again with Wudhu or Ghusl.
681. If a person was sure that water was not harmful to him, and he did Ghusl or Wudhu, but later realised that water was harmful to him, his wudhu and Ghusl will be void.
682. If a person fears that if he uses water for Ghusl or Wudhu, he will be involved in hardship because of thirst, he should perform tayammum. Tayammum is permissible in the following three cases:
If he fears that by using up the water for Ghusl or Wudhu he will suffer an acute thirst, which may result in his illness or death, or it may cause intolerable hardship.
If he fears that his dependents whose protection is his responsibility, may become ill or die due to thirst.
If he fears that others, human beings or animals, may die or suffer some illness or become unbearably restless and distressed due to lack of water.
Apart from these three conditions mentioned, it is not permissible to perform
tayammum when water is available.
683. If besides the Pak water which a person has for Wudhu or Ghusl he also has najis water enough for drinking, he should keep the Pak water for drinking and pray with tayammum. When water is required for other people attached to him, he would keep Pak water for Wudhu and Ghusl and let them quench their thirst with najis water, regardless of whether they know about the najasat or not, or whether they care about it or not. If water is required for an animal or a minor child, it should be given najis water to drink and Pak water be used for Wudhu or Ghusl.
684. If the body or dress of a person is najis and he possesses only as much water as is likely to be exhausted if he does Ghusl or Wudhu, and no water would be available for making his body or dress Pak, he should make is body or dress Pak and pray Namaz with tayammum. But if he does not have anything upon which he would do tayammum, then he should use the water for Ghusl and Wudhu, and pray with najis body or dress.
685. If a person possesses such water or container which is not permitted to use, like when they are usurped (Ghasbi) he should perform tayammum instead of Ghusl and Wudhu.
686. When the time left for Namaz is so little that if a person does Ghusl or Wudhu he would be obliged to offer the entire prayers or a part of it after the prescribed time, he should perform tayammum.
687. If a person intentionally delays offering the prayers till no time is left for Ghusl or Wudhu, he commits a sin, but the prayers offered by him with tayammum will be valid, although recommended precaution is that he should give Qadha of the prayers.
688. If a person doubts whether any time will be left for prayers if he does Ghusl or Wudhu, he should perform tayammum .
689. If a person performs tayammum owing to shortage of time and after the Namaz he had an opportunity to do Wudhu but did not do so till the water he had is no longer with him, he will have to perform a new tayammum for subsequent prayers, even if the first tayammum had not become void, provided, of course, that tayammum continues to be his religious obligation.
690. If a person has water, but because of shortage of time he prays with tayammum and while in prayers, the water he had goes out of his possession, he will, as per recommended precaution, do tayammum again for the subsequent prayers, provided that his religious obligation continues to be tayammum.
691. If a person has only just enough time that he may perform Wudhu or Ghusl and offer prayers without its Mustahab acts like Iqamah and Qunut, he should do Ghusl or Wudhu, whichever is then necessary, and pray without those Mustahab parts. In fact, if for that purpose, he has to avoid the next Sura after al-Hamd, he should do so after doing Wudhu or Ghusl.