Sunan Ibn Majah
3397
Sahih+3

It was narrated from ‘Abdullah bin Abu Qatadah, from his father, that he heard the Messenger of Allah (ﷺ) say:“Do not combine fresh dates and unripe dates, or raisins and dates; rather make Nabidh with each one of them on its own.”

SahihAl-Albani
SahihMuhammad Fouad Abd al-Baqi