مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3084
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn 'Abbas (رضي الله عنه) said: The Messenger of Allah (ﷺ) forbade mixing fresh dates and dried dates, and mixing raisins and dried dates. And he wrote to the people of Jurash (saying): Do not mix raisins and dried dates.
Musnad Ahmad 3110Its isnad is saheeh, Muslim (1990)]