833. If a person doubts whether his clothing is made from an animal whose meat is permissible (to eat) or forbidden, it is permissible to pray with it, regardless of whether it was acquired in an Islamic country or a non-Islamic country.

700. If a person has certainty that tayammum on a particular substance is valid, and performs tayammum on it, realizing later on that tayammum on that substance is invalid, he must offer once again all the prayers that he offered with such a tayammum.

701. The thing on which a person performs tayammum and the place in which it is situated should not be usurped. Hence in a person performs tayammum on usurped sand, or pours the sand that he owns on another person’s property without his permission, and then performs tayammum on it, his tayammum will be invalid. However, the condition that the location of the one performing tayammum not be usurped is not legitimate for the validity of the tayammum.

834. It is permissible to pray with an oyster shell or articles made from it, such as buttons.

702. Precaution dictates that the tayammum performed in a usurped area is invalid. An example of this would be a person who strikes his hands on his own land, and then enters another person’s property without his permission, and wipes his hands on his forehead.

835. There is no harm in wearing pure fur during prayer, but based on obligatory precaution, one should not pray wearing the skin of a squirrel.

836. If a person prays wearing clothing made from an animal whose meat is forbidden, be it forgetfully or due to ignorance (of it being made from such an animal), it is not necessary for him to repeat his prayer. The recommended precaution however, is that he repeats it. Similarly, it is not necessary to repeat it if he is an excusable ignorant with respect to the ruling.

837. It is forbidden for a man to wear gold embroidered clothing, and doing so during prayer invalidates it. There is no problem however for women to wear them in or outside of prayer.

703. The tayammum performed on a usurped thing or a thing that is located on a usurped property is invalid, even if the person does not know of it being usurped. The same will apply to a tayammum performed in a usurped area, based on obligatory precaution.
However if the person forgets that it is usurped or becomes negligent of it, it will be valid, unless he himself is the usurper and has not repented for usurping it. In this case the tayammum performed on a usurped thing or a thing which is on usurped land is invalid. As for the case wherein he has repented, his tayammum will similarly be invalid based on obligatory precaution.

704. If a person is imprisoned in a usurped area, and the water and sand in the area are both usurped, he should offer his prayer with tayammum.

838. Wearing items made of gold, such as a golden necklace, a golden wrist watch, golden glasses, a gold ring or items similar to these is forbidden for men, and if a man prays while wearing them, his prayer is invalid. However, there is no problem in women utilizing such items in or outside of prayer.

839. If a man wears an item made of gold—for example a gold ring—forgetfully, or he does not know it is made of gold, or doubts whether it is made of gold or not, and prays with it, his prayer is valid.

705. Obligatory precaution dictates that the thing on which tayammum is performed should have some dust which sticks to the hands. It is also recommended to shake one’s hands after striking them on the thing.

840. The clothing of a man who is praying should not be made from pure silk. Based on obligatory precaution, the same applies to articles such as a kufi or a waistband. In fact, it is forbidden for men to wear clothes made from pure silk outside of prayer as well.

841. If a part or all of the lining of a man’s clothing is made from pure silk, it is forbidden for him to wear it, and doing so during prayer will invalidate it.

842. If a person does not know whether an article of clothing is made from pure silk or not, wearing it is permissible and there is no problem in doing so during prayer.

843. There is no problem in having a pure silk handkerchief or similar article in one’s pocket and prayer is not invalidated with it.

844. There is no problem in a woman utilizing clothing made from pure silk in and outside of prayer.

845. There is no problem in wearing clothing that is gold embroidered, made from pure silk, or usurped, if one is compelled to do so. Additionally, if one is compelled to wear clothes, and possesses no clothes until the end of the prayer time, other than the aforementioned articles, he can pray in such clothes.

706. It is makrÙh to perform tayammum on the earth in a pit, sand on the streets, and saline earth which is not covered with a layer of salt. If it is, the tayammum performed on it is invalid.