Sunan an-Nasa'i, Book 51, Hadith 18 (In-Book) ⓘ
It was narrated that Ibn 'Abbas said: "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.'"
أَخْبَرَنَا وَاصِلُ بْنُ عَبْدِ الأَعْلَى، عَنِ ابْنِ فُضَيْلٍ، عَنْ أَبِي إِسْحَاقَ، عَنْ حَبِيبِ بْنِ أَبِي ثَابِتٍ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ نَهَى رَسُولُ اللَّهِ صلى الله عليه وسلم 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 " .
also referenced under: Hadith 5557 (Reference) & Volume 6, Book 51, Hadith 5559 (DarusSalam)