Musnad Ahmad 32:1030

Isma'il narrated to us, Sulayman al-Taymi narrated to us, Anas ibn Malik narrated to us, saying: "I was standing among the people of the tribe, giving them a drink from a *fadikh* (a beverage made from dates) of theirs, when a man came and said: 'Indeed, alcohol has been prohibited.' They said: 'Pour it out, O Anas.' So I poured it out. I said to Anas: 'What was it?' He said: 'Unripe dates and ripe dates.' Abu Bakr ibn Anas said: 'It was their alcohol on that day.'" He said: And a man narrated to me from Anas that he also said that.