Purity (, ṭahāra(h)) is an essential aspect of Islam. It is the opposite of najāsa, the state of being ritually impure. It is achieved by first removing physical impurities (for example, urine) from the body, and then removing ritual impurity by means of wudu (usually) or ghusl.
In the Quran
The Quran says: and also there is one verse which concerned with Taharah or purity and impurity of Humans:
Importance in Islam
Observing cleanliness of the soul, the clothes, and the surroundings is obligatory upon every Muslim, and this is considered one of the pillars of Islam.
Before offering prayers, it is necessary to perform wudu, and in certain cases, ghusl. The purifying agent is always clean water. However, during times when water is not available or is scarce, symbolic wudu and ghusl can be performed with clean dry earth which is known as Tayammum.
If the body or clothes show traces of urine, feces, semen or alcohol, then taharah becomes essential. Many juridical opinions add blood and pus to that list. The clothes should be washed and the affected part of the body cleaned with pure water, or the whole body given a ghusl as the case may be.
Most Muslims believe that they must perform a ritual cleansing with water (Wudu) before touching a copy of the Quran, although this view is not universal.
When in a state of major ritual impurity, one should not even recite the Quran, let alone touch it.
In a state of minor ritual impurity, it is forbidden (in some schools, makruh) to handle the Quran and to read it, and is considered to be acceptable (neutral, mubah) to recite it, although it is better liked (recommended, mustahabb) to be ritually pure.
A mushaf is only a Quran if it is the Arabic Quranic text, and a book that contains more than 50% non-Quranic material is not viewed as a Quran for the above purposes, even if it contains verses of the Quran or the entire Quranic text. Examples would be a tafsir, or a translation of the Quran such as Yusuf Ali's (with commentary) which contains over fifteen times as much text in footnotes than it does in Quranic text or Quranic interpretation in either Arabic or English, or a book of hadith that contains Quranic verses embedded in the narrations.
Shia views
In respect to purity of non-Muslims, some of the Shia Muslims believe in the impurity of non-Muslims. However, there are others which believe in the purity of non-Muslims.
Some people such as Shaykh Tusi (d. 1076) believed that it is not permissible to eat with kuffar or non-Muslims. Considering non-believers as najis has been prevalent until twentieth century. Muhaqqiq al-Hilli (d. 1277) also believes in impurity of non-believers. Most maraji (authorities) such as Ruhollah Khomeini (d. 1986), Mohammad-Reza Golpaygani (d. 1993), and Abu al-Qasim al-Khoei (d. 1992) believed in the impurity of kuffar, including People of the Book. Al-Khoei pointed out precaution ruling in the subject.
However, there are some authorities such as Muhammad Baqir al-Sadr (d. 1980), Mohammad Fazel Lankarani (d. 2007), Ali al-Sistani, and Ali Khamenei, who do not believe in the impurity of People of the Book.
Some scholars such as Mohsen Fayz Kashani (d. 1680) and Sulayman ibn Abdullah Mahuzi (d. 1708) did not believe in the impurity of non-believers, and particularly non-People of the Book. For instance, Kashani believes that the impurity of kuffar is spiritual and internal, so there is no need to wash after touching them. This group believes in the purity of non-Muslims and of all humans. Mohammad Ebrahim Jannaati, Mohammad Hussein Fadlallah (d. 2010), Mostafa Mohaghegh Damad and Yusuf Sani‘i are part of this group.
Sunni views
Sunni Islam has its own hygienical jurisprudence. It is preferable for a Sunni Muslim to remove the hair directly below the navel and under the arms also as trimming the nails once a week. Leaving hair and nails is permissible after 15 days and disliked after 40 days. The best day for removing needless hair and cutting nails is Friday. It is permissible to use shaving cream to remove needless hair. Needless hair and nails should be buried to prevent illnesses from spreading. Cutting eyebrows is permissible if they are too long. Sunni women should put their nails and hair removed from below the navel, and under the arms in a place where no non-permissible men can see it.
Personal grooming is also a matter of focus in Islam, and comprises all the ritual purity practices of prophets known as fitra. Allowing a beard to grow while trimming the moustache is emphasized with it being seen as mandatory by some respected Sunni scholars from the 4 major Sunni schools of jurisprudence.