The Messenger of Allah [SAW] forbade soaking raisins and dried dates together, and he forbade soaking Al-Busr and dried dates together. (Using translation from Nasāʾī 5556)
عَنْ رَسُولِ اللهِ ﷺ «أَنَّهُ نَهَى أَنْ يُنْبَذَ الزَّبِيبُ وَالتَّمْرُ جَمِيعًا وَنَهَى أَنْ يُنْبَذَ الْبُسْرُ وَالتَّمْرُ جَمِيعًا»