Sahih Muslim
The Book of Drinks (Kitab Al-Ashriba)
Book Number: 023 / Hadith Number: 4888
Anas b. Malik is reported to have said that Allah's Messenger (may peace be upon him) had forbidden to mixture fresh dates and unripe dates and then drinking (the wine prepared out of it), and that was their common intoxicant when liquor was prohibited.