Sahih Muslim
The Book of Drinks (Kitab Al-Ashriba)
Book Number: 023 / Hadith Number: 5030
Anas reported that Allah's Messenger (may peace be upon him) breathed three times (outside the vessel) in the course of a drink and said: It is more thirst- quenching, healthier and more wholesome. Anas said: So I also breathe three times in the course of a drink.