Ya'qub bin Ibrahim bin Sa'd يعقوب بن إبراهيم بن سعد بن إبراهيم · The Book of Drinks

"Unripe dates and dried dates are Khamr." Al-A'mash narrated it in Marfu' form.

"The Messenger of Allah forbade mixing Al-Busr with dried dates, or raisins with dried dates, or raisins with Al-Busr, and he said: 'Whoever among you (wants to) drink them, let him drink each one of them on its own: dried dates on their own, or Al-Busr on their own, or raisins on their own."