Ibn 'Abbas reported that Allah's Apostle ﷺ forbade the mixing of dates and grapes together, and mixing of unripe dates and ripe dates together (for preparing Nabidh), and he wrote to the people of Jurash (in Yemen) forbidding them to prepare the mixture of dates and grapes.  

نَهَى النَّبِيُّ ﷺ أَنْ يُخْلَطَ التَّمْرُ وَالزَّبِيبُ جَمِيعًا وَأَنْ يُخْلَطَ الْبُسْرُ وَالتَّمْرُ جَمِيعًا وَكَتَبَ إِلَى أَهْلِ جُرَشَ يَنْهَاهُمْ عَنْ خَلِيطِ التَّمْرِ وَالزَّبِيبِ  

"The Messenger of Allah [SAW] forbade Ad-Dubba', Al-Hantam, Al-Muzaffat, and An-Naqir, and that Al-Busr be mixed with dried dates, and that raisins be mixed with dried dates, and he wrote to the people of Hajar saying: 'Do not mix raisins and dried dates together.'"  

نَهَى رَسُولُ اللَّهِ ﷺ عَنِ الدُّبَّاءِ وَالْحَنْتَمِ وَالْمُزَفَّتِ وَالنَّقِيرِ وَعَنِ الْبُسْرِ وَالتَّمْرِ أَنْ يُخْلَطَا وَعَنِ الزَّبِيبِ وَالتَّمْرِ أَنْ يُخْلَطَا وَكَتَبَ إِلَى أَهْلِ هَجَرَ أَنْ لاَ تَخْلِطُوا الزَّبِيبَ وَالتَّمْرَ جَمِيعًا  

"The Messenger of Allah [SAW] forbade Ad-Dubba', Al-Hantam, Al-Muzaffat, and An-Naqir, and that Al-Busr be mixed with dried dates, and that raisins be mixed with dried dates, and he wrote to the people of Hajar saying: 'Do not mix raisins and dried dates together.'" (Using translation from Nasāʾī 5557)  

نَهَى النَّبِيُّ ﷺ «عَنِ الدُّبَّاءِ وَالْحَنْتَمِ وَالْمُزَفَّتِ وَالنَّقِيرِ وَعَنِ الْبُسْرِ وَالتَّمْرِ أَنْ يُخْلَطَا وَعَنِ الزَّبِيبِ وَالتَّمْرِ أَنْ يُخْلَطَا وَكَتَبَ إِلَى أَهْلِ هَجَرَ أَنْ لَا تَخْلِطُوا الزَّبِيبَ وَالتَّمْرَ جَمِيعًا»