Abu Sa'id reported that Allah's Apostle ﷺ prohibited that fresh dates and grapes be mixed together and that fresh dates and unripe dates be mixed together.
أَنَّ النَّبِيَّ ﷺ نَهَى عَنِ التَّمْرِ وَالزَّبِيبِ أَنْ يُخْلَطَ بَيْنَهُمَا وَعَنِ التَّمْرِ وَالْبُسْرِ أَنْ يُخْلَطَ بَيْنَهُمَا