Purifying Things
There are 12 things which make impure objects pure.
1. WATER
Water is of two kinds
A. Mutlaq (pure water)
Mutlaq is of 5 kinds:
  1. Rain water
  2. Running water
  3. Well water
  4. Still water about Kur or more than a Kur (Abe Kathir); and
  5. Still water less than a Kur(Abe Kaleel).
B. Muzaf (mixed water)
Water cleanses a Najis thing on the condition that water is (1) Mutlaq, and (2) clean (Tahir ), and (3) does not become Mozaf by coming into contact with that Najasat, and (4) all the Najasat is washed away from that Najis thing.

Rain water, running water (like sea, river, stream, spring etc.) and well water make things clean if washed once after removing the Najasaat. But if any thing becomes Najis by urine it must be washed twice. It is better to wash twice even in other Najasaats.

Clothes should be squeezed after every washing as described above.

Still water which is just a Kur or more than a Kur, also, makes things clean in the same way.

These waters cannot be unclean by mere contact with Najasaat. They will be unclean if either their taste, color or smell is changed by that contact.

Still water which is less than a Kur becomes unclean by just coming into contact with a Najasaat. To cleanse with clean still water, it is necessary to wash two times after removing the Najasaat. It is better to wash three times.

The water running from the pipes in the houses is treated as river water so long as it is running.

Pots must be cleansed three times with water which is less than a Kur, and once if it is washed in Kur or running water.

If a Pig licks the pot, then it should be washed seven times whether the water is running or Kur or less than that.

The same is the rule if a rat dies in a pot.

If a Dog licks the pot, it should be rubbed with wet clean earth thoroughly; then, after washing away the earth, it should be washed twice with water which is less than a Kur, or once in Kur or running water.

If a pot becomes Najis by liquor, it must be washed three times, whatever the kind of water.

Note: A Kur is about 384 liters of water.
2. EARTH
The earth makes clean the sole of the shoe or feet, but there are four conditions for it:
  1. The Najasaat must have been contacted from walking on the earth;
  2. It is removed by walking on the earth;
  3. The earth is clean;
  4. and Dry.

Note: This rule does not apply to the end of the stick or wheels of car or carts etc.
3. SUN
The sun makes clean those things which cannot be moved like wall, tree, earth etc. If the Najasaat is removed, and the place or tree etc. is wet, and then it becomes dry by direct rays of the sun, it becomes clean. If it dries by hot air combined with the sun's rays, or just by hot air, or by sun's heat without direct rays, it will not be clean.
4. ISTIHALA
It means "change". If a najis thing is changed into a clean thing (chemically), it will become clean. For example, a Najis stick burnt turns to ashes or if a dog after death is changed into earth, that earth will be clean.
5. INQUILAB
It is similar to the Istihala. The difference is that in Istihala, the shape and form, all are changed, while in Inquilab, only the properties are changed. Its only example: If wine becomes vinegar, it is Inquilab. By Inquilab, it will become clean.

Note: If grape juice is fermented, either by fire or by itself, it is Haram to drink. But if that fermented liquid is boiled on fire and its two-thirds are evaporated the remaining one-third will become Halal.
6. INTIKAL
It means to change place. If a mosquito sucks the blood of a man and there is a gap of time, so that the blood is called the blood of mosquito, it will become clean.
7. ISLAM
Kafir becomes clean after accepting Islam.
8. TABA-IAT
  1. When a Kafir becomes Muslim, his minor children become clean automatically.
  2. If a well becomes Najis and the water is taken out of it until it becomes clean, then the wall of the well, the bucket and the rope will become clean automatically.
  3. While washing Najis things our hands become unclean; but when that thing becomes clean, our hands will become clean automatically.
  4. If the wine becomes vinegar and thus becomes clean, the pot in which it was, will become clean automatically.
  5. Wood plank or cement/stone slabs upon which the body of a dead Muslim is washed, as well as the piece of cloth used to cover hiss hidden parts, and also the hands of the person washing the body become clean when the Ghusl-e-Meyyit is completed.
9. ZAWAL-E-AIN
If there is any Najasaat on the body of an animal, it will become clean if that Najasaat is just removed or rubbed out from his body. Likewise, the inner parts of human body, like mouth and stomach, become clean if the Najasaat is just removed from them. Eyelids, lips and dentures are not included in this rule.
10. ISTIBRA
The urine and the stool of the animal which eats the refuse of man are Najis; and the only way of its Taharat is Istibra; i.e. guarding it from above mentioned Najis feed for a certain prescribed period. This period is 40 days for a Camel; 30 days for a Cow; 10 days for a Sheep and Goat; 5 to 7 days for a Duck and 3 days for a Hen.

If any of these animals are kept away from the refuse of man for the prescribed period its urine and stool become Tahir, provided that, at the end of that period, they are no more called 'refuse eating animals'.
11. GHAIBAT-E-MUSLIM
If there is a Muslim, who is strict follower of the Shariat; and any of his clothes or things becomes Najis, then he goes out of your sight long enough to enable him to make it clean, then he comes back and you see him using that cloth in Namaz, for example, then you must believe that he has cleansed that cloth, otherwise, he would not have used it in Namaz. It is called Ghaibat -e- Muslim, which means "Absence of Muslim".
12. FLOWING OF BLOOD
When a Halal animal is slaughtered according to the rules of Sheriat, and its blood flows out of its body in such a quantity which is normal in that kind of animal, the blood which remains in its body becomes Clean.

But that blood which remains in those organs of body which are Haram (like Spleen, Bladder etc.) must be avoided.