Yahya narrated that 'Abdullah bin Abi Qatadah said to him from his father, that:

The Prophet ﷺ forbade mixing Az-Zahuw and dried dates, and mixing Al-Busr and dried dates, and he said: "Soak each one of them on its own in vessels that are tied shut."

أَخْبَرَنَا يَحْيَى بْنُ دُرُسْتَ، قَالَ حَدَّثَنَا أَبُو إِسْمَاعِيلَ، قَالَ حَدَّثَنَا يَحْيَى، أَنَّ عَبْدَ اللَّهِ بْنَ أَبِي قَتَادَةَ، حَدَّثَهُ عَنْ أَبِيهِ، أَنَّ النَّبِيَّ ﷺ نَهَى عَنْ خَلِيطِ الزَّهْوِ وَالتَّمْرِ وَخَلِيطِ الْبُسْرِ وَالتَّمْرِ وَقَالَ " لِتَنْبِذُوا كُلَّ وَاحِدٍ مِنْهُمَا عَلَى حِدَةٍ فِي الأَسْقِيَةِ الَّتِي يُلاَثُ عَلَى أَفْوَاهِهَا " .