It is narrated from Ata bin Yasar (may Allah be pleased with him) that the Messenger of Allah (ﷺ) forbade making nabidh by mixing together dates and partially ripe dates, and by mixing together dry dates and nearly ripe dates.
Hadith Referenceمسند الإمام الشافعي / كتاب الأشربة والأنبذة والأوعية / 1548
Hadith Takhrijصحیح ثبت موصولا اخرجه البيهقي في المعرفة السنن والآثار (5233) مرسلا وعبدالرزاق (16982) موصولا۔