Purity 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 from the body, and then removing ritual impurity by means of wudu or ghusl.
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 as one of the pillars of Islam. Before offering prayers, it is necessary to perform wudu, and in certain cases, both wudu and 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. A person must not touch the Quran if the person is not in the state of Tahara. The Quran says: None shall touch it but those who are clean. When in a state of janaba, one is not allowed even to recite the Quran, let alone touch it. In a state of minor ritual impurity, it is forbidden to handle the Quran and to read it, and is considered to be acceptable to recite it, although it is better liked 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 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, the majority of Shia Muslimsbelieve in the impurity of non-Muslims. However, there is a minority among Shia which believe in purity of non-Muslims.
Cleaning teeth is also very important. Muhammad is reported to have said that the angels of mercy turn away from a person whose mouth emits foul smell because of unclean teeth. It is not only unhygienic to neglect cleaning teeth but also an anti-social habit likely to repel people from one's presence. It is narrated by Ibn Majah to "use the Miswaak, for verily, it purifies the mouth, and it is a Pleasure for the Lord. Jibreel exhorted me so much to use the Miswaak that I feared that its use would be decreed obligatory upon me and upon my Ummah. If I did not fear imposing hardship on my Ummah, I would have made its use obligatory upon my people. Verily, I use the Miswaak so much that I fear the front part of my mouth being peeled."
Smoking
The mixed views on the subject came about because tobacco had not been introduced to Arabia at the time when the Quran was written in the 7th century CE. Therefore, one cannot find a verse of Quran or words of Muhammad saying clearly that "Smoking is forbidden." However, there are many instances where the Quran gives general guidelines, and calls upon Muslims to use their reason and intelligence, and seek guidance from Allah about what is right and wrong. It is universally understood that smoking causes a number of health problems that often ultimately result in death: smoking is, depending on the madhhab, considered to be either makruh or haram, but in Sunni madhhabs it is not considered to cause one to lose ritual purity.
