Sahih Bukhari
Sahih Bukhari Volume 001, Book 004, Hadith Number 155.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 04. Ablutions (Wudu')
Narated By Abu Qatada : Allah's Apostle said, "Whenever anyone of you drinks water, he should not breathe in the drinking utensil, and whenever anyone of you goes to a lavatory, he should neither touch his penis nor clean his private parts with his right hand."