4. Method of Ablution (wuzu)
Surah No. 5, Al Maaeda, Part of Ayat No. 6
يَا أَيُّهَا الَّذِينَ آمَنُواْ إِذَا قُمْتُمْ إِلَى الصَّلاةِ فاغْسِلُواْ وُجُوهَكُمْ وَأَيْدِيَكُمْ إِلَى الْمَرَافِقِ وَامْسَحُواْ بِرُؤُوسِكُمْ وَأَرْجُلَكُمْ إِلَى الْكَعْبَينِ
O Believers ! When you prepare for prayer (Salat) wash your faces and your hands to the elbows; Pass your wet hands over your head and wash your feet to the ankles .
Ablution (Wuzu) is required to be done when a person is going to perform salat or recite Quran or before bathing (Gusl). It remains valid upto 24 hours but it is nullified if blood or pus is drawn, if one urinates, passes gas through anus or passes stool or falls into sleep.
How to perform the Wuzu is mentioned below in one of the Hadis :
Chapter Nu. 1, Hadis No. 0111, Sunan Abu Dawud
Narrated Ali ibn AbuTalib: Abdu Khayr said: Ali came upon us and he had already offered prayer. He called for water. We asked: What will you do with water when you have already offered prayer? - Perhaps to teach us. A utensil containing water and a wash-basin were brought (to him). He poured water from the utensil on his right hand and washed both his hands three times, rinsed the mouth, snuffed up water and cleansed the nose three times. He then washed his face three times, and washed his right hand three times and washed his left hand three times. He then put his hand in water and wiped his head once. He then washed his right foot thrice and left foot thrice, then said: If one is pleased to know the method of performing ablution of the Apostle of Allah, this is how he did it.