Wudhu (Arabic: الوضوء al-wudu ', Persian: آبدست ābdast, Turkish: abdest, Urdu: وضو wazū') is one way to purify the body with water. A Muslim ablutions are obligated each will perform the prayer. Wudhu can also use a dust called tayammum.
Water may be used
* Water wells
* Waterfalls, sea or river
* Water from melting snow or ice cubes
* Water from a large tank or pond
Water that should not be used
* Water is not clean or there is unclean
* Water or fruit trees
* Water that has changed color, taste and smell and become thick because something has been immersed in it
* Water with small amounts (less than 1000 liters), exposed to something that is not clean like urine, blood or wine or have a dead animal inside
* Water used Ablution
Water former ablution, if slightly, it may not be used, and includes as musta'mal water, as the hadith: Abdullah ibn Umar. Said, "Rasulullah SAW had said:" If the water has reached two qullah, not containing impurities. In other lafadz: "no unclean thing." (Abu Dawud, Tirmidhi, Nisaa'i, Ibn Maja)
In the opinion of four madhhabs:
1. Al-Ulama Hanafiyah
According to this sect that the musta'mal is water wet body and not just any water remaining in the container. Water that has direct musta'mal law when he was dripping from the body as the rest of wudu `or shower. Musta'mal water is water that has been used to lift hadats (`ablution for prayer or shower required) or for qurbah. Intention to perform ablution or bath `sunna sunnah. While the water in the container does not become musta'mal. For them, this ruling musta'mal holy water but could not purify. That means no unclean water is sacred, but can not be used again to perform ablution or bath `.
2. Al-Ulama Malikiyah
Musta'mal in their understanding of water is water that has been used to lift hadats `good ablution or bath. And do not distinguish whether the wudu `or bath obligatory or sunnah. Also have been used to eliminate khabats (goods unclean). And as Al-Hanafiyah, they say 'that which is just musta'mal former ablution or bath water that dripped from a person's body. But the difference is that in their opinion musta'mal water is sacred and purify. That is, can legitimately be used and used again for ablution or bathing `sunna as long as there are other water even with karahah (less preferred).
3. Ash-Shafi `Ulama iyyah
Musta'mal water in the sense they are a bit of water that has been used to lift hadats in fardhu taharah from hadats. The water was a little musta'mal when material is picked up with the intention of wudu `or bath to wash their hands even for that is part of the sunnah wudu`. But if the intention is not just for menciduknya associated with wudu `, it is not yet considered musta'mal. Included in musta'mal water bath is the bath water either people who converted to Islam or dead person or his bathrobe bathrobe people who recover from the madness. And the water was only when it is said musta'mal loose or dripping from the body. Musta'mal water in the schools of this ruling can not be used for ablution `or to bathe or to wash the impure. Because of their status but does not purify the sacred.
4. Al-Ulama Hanabilah
Water musta'mal in the sense that they are water has been used for purification of small hadats (wudu ') or large hadats (shower) or to eliminate the odious on washing the last of the seven times of washing. And for that water did not change either the color, flavor or fragrance. In addition any excess water bodies including water bath musta'mal. But if the water used for washing or wiping sesautu outside the framework of worship, then do not say musta'mal water. Like menuci not advance in a series of worship ritual ablution `. Or hand washing is also no connection with religious ritual ablution `.
* The water that remains after the animals drank illicit such as dogs, pigs or animal prey
* Water was left by someone who was drunk with wine
Source : http://id.wikipedia.org/wiki/Wudhu