After applying piped water [to a carpet], removal of the used water is not necessary; rather, after the inherently najis substance has been removed, water has reached the najis area, and the used water has been moved from this area by pressing with the hand while connected to piped water; the carpet becomes pure.
The Earth as a Purifier
If a person walks on the ground and the sole of his shoes/foot becomes najis due to coming in contact with a najis thing, it becomes pure if he walks about ten steps on dry pure ground and the inherently najis material is removed.
Asphalt, Not a Purifier
Grounds paved with asphalt or covered with tar do not purify the sole of feet or the bottom of shoes.
The Sun as a Purifier
The sun purifies the ground and all irremovable objects such as buildings, objects connected to them and/or whatever is fixed inside of them — such as timbers, doors and so forth. These things are purified by sunshine provided that at first the inherently najis substance is removed, and then they are wet and in the sun until it dries them up.
Alcohol in Medicine
If one knows that the alcohol used in a medicine is originally liquid and, according to the experts, intoxicant as well, it is najis by obligatory caution.
The Remaining Color of Blood
After washing the dress stained with blood, if no blood remains; rather it is just the color, it is pure.
Blood in an Egg
The spot of blood in an egg is considered pure, but eating it is ḥarām.
Coagulated Blood in the Mouth
The food which comes into contact with the blood coagulated in the gums is pure and there is no problem in swallowing it.
Small Pieces of Body Skin
In general, small [separated] pieces of body skin are pure even if they are plucked in case it was time for their fall. However, one should avoid those plucked before their fall time.
Dropping of a Bird
The droppings of birds — whether or not their meat is ḥalāl — are pure.
Purity of the People of the Book
The people of the book are inherently pure.
Meat Imported from Non-Islamic Countries
It is impermissible to eat meat which is imported from non-Islamic countries unless its ritual slaughtering is verified. However, as far as purity is concerned, if one is not certain that it has not been slaughtered ritually, it is considered pure.
To Inform Others about Najāsah
If a guest makes any household appliance of his host najis, it is not obligatory for him to inform the host about it unless it is something edible or drinkable, or it is a utensil used for food.
Falling a Sacred Thing in the Sewerage System
If, say, some verses of the Holy Qur’an, or a piece of writing containing some verses falls in a toilet well, the person for whom this fact is proved in a shar‘ī way should not use the toilet until he is sure it is decayed and destroyed. However, it is not necessary for him to inform others and those who are not aware have no duty in this regard. It is not necessary either to empty the well if it is unbearably difficult.
Waswās or Obsession
According to the holy shariah as far as purity and najāsah are concerned all things are considered pure i.e. whenever there is doubt as to whether or not something has become najis, it should be ruled as not najis. Those individuals who are too sensitive to purity affairs (who are referred to in jurisprudential terminology as waswāsī or obsessive) should always consider things as not najis even though they might be certain about najāsah, except in situations when they by their eye watch that something has become najis so that if other normal people see it they will also admit that najāsah has transmitted. It is only in this case that they should consider things as najis and the application of this rule on such people should continue until this abnormal sensitivity totally disappears.