Issue 520: One who cannot make their forehead reach the ground, must bend as mach as they can, and put the clay disk or whatever prostration is valid on, high on something and place their forehead on it such that any observer would confirm they are prostrating, but they must put their palms, knees and big toes on the ground as usual.

Issue 521: One, who cannot bend down for prostration, must sit down and bend their head, but the obligatory precaution is to lift the clay disk as high as they are able to bend their forehead on it.

Q522: Sometimes, while in the first prostration, one's forehead touches the clay disk twice. Are these touches accounted as two prostrations?

A: It is accounted one prostration, because the second touch has not been intentional and voluntary, so it is not taken into consideration.

Q523: Sometimes, there appears some acne on the forehead which causes pain while prostrating. Is it allowable to lean one's forehead on the clay disk in such a situation?

What is the case of the prayer of a person with such acne, if after raising their head they see that the blood from those acnes has stained the clay disk?

A: While prostrating, it is not necessary to put one's entire forehead on the clay disk or any thing else on which prostration is valid, and it would suffice to put just a part of it on the clay disk; But it will not suffice if one puts any part of the body other than their forehead on the clay disk, so to put their foreheads in a slopping position on the clay disk is not forbidden. When the clay disk becomes impure with blood stains, it is not permissible to prostrate on it, because it is a necessary condition for the place of prostration to be pure.

The blood which comes out of a wound, does not invalidate the prayer provided that the stain is smaller in size than a dirham (a coin with a diameter of nearly two centimeters), but if it makes the place impure for the next prostration, one is not allowed to pray with that, because the place of prostration must be pure.

Q524: Is it allowable to prostrate on one's nails if while praying they lose the thing on which prostrating is valid and do not find such a thing again?

A: If they have enough time for offering prayers, they must cut their prayers and find something on which prostrating is valid, and then redo their prayer, but if they have little time, or if despite cutting their prayer, they do not find any thing on which prostration is valid, they should prostrate on their clothes; if this is not possible either, they should prostrate on the back of their hands and if this is also not possible they can use any mineral stone such as agate rings etc.

Q525: What is the case of prostrating on cement, tile, baked lime or gypsum? What about performing Tayammum on them?

A: It is not valid to prostrate on cement, tile, and the like, which have undergone lots of changes and they cannot be accounted as earth, but as for baked lime, back gypsum, and the like, such as raw lime and gypsum, prostrating on them is permissible, and Tayammum is treated like prostration in all these cases.