(5) باب كَرَاهَةِ انْتِبَاذِ التَّمْرِ وَالزَّبِيبِ مَخْلُوطَيْنِ
Abu Qatada, on the authority of his father, reported Allah's Messenger (ﷺ) having said this:
Do not prepare Nabidh by mixing nearly ripe dates and fresh dates together, and do not prepare Nabidh by mixing grapes and dates together, but prepare Nabidh from each (one of them) separately.
Reference: Sahih Muslim 1988 a
In-book reference: Book 36, Hadith 28
USC-MSA web (English) reference(deprecated numbering scheme): Book 23, Hadith 4904