Musnad Ahmad 32:1264

'Abd al-Samad narrated to us, my father narrated to me, Abu 'Isam narrated to us, from Anas ibn Malik, who said: The Messenger of Allah (peace and blessings of Allah be upon him) used to breathe three times while drinking, and he would say: "It is more quenching, more wholesome, and more digestible." Anas said: "And I breathe three times."