From Sahih Bukhari (Hadith 5582):
Narrated Anas bin Malik:I was serving Abu 'Ubaida, Abu Talha and Ubai bin Ka`b with a drink prepared from ripe and unripe dates. Then somebody came to them and said, "Alcoholic drinks have been prohibited." (On hearing that) Abu Talha said, "Get up. O Anas, and pour (throw) it out! So I poured (threw) it out
Reference: Bukhari 5582