Sahih Muslim Book 23, Hadith Number 4985.
Chapter : It is good to drink milk.
Abu Huraira reported that Allah’s Messenger (may peace be upon him) was presented two cups at Bait al-Maqdis on the night of Heavenly Journey, one containing wine and the other containing milk. He looked at both of them, and be took the one containing milk, whereupon Gabriel (peace be upon him) said: Praise is due to Allah Who guided you to the true nature; had you taken the one containing wine, Your Umma would have gone astray.