Musnad Ahmad 32:945

Yahya narrated to us, he said: At-Taymi narrated to us, from Anas, who said: "I was standing over the people, giving them to drink from a *fadikh* (a beverage) made of dates." He said: Then a man came and said: "Indeed, alcohol has been prohibited." They said: "Pour it out, O Anas." So I poured it out. I said: "What was their drink?" He said: "Unripe dates and fresh dates." Abu Bakr ibn Anas said: "It was their alcohol on that day," and Anas was listening and did not deny it. And some of those who were with us said: Anas said: "It was their alcohol on that day."