The Messenger of Allah ﷺ forbade soaking unripe dates and ripe dates together, and raisins and dates together. Ata said, "Yes."
حدثنا عفان حدثنا همام قال سأل سليمان بن موسى عطاء وأنا شاهد قال
أن رسول الله ﷺ نهى أن ينبذ البسر والتمر جميعا والزبيب والتمر جميعا قال عطاء نعم
Its isnad is sahih. Sulayman bin Musa al-Ashdaq al-Umawi, the jurist, was deemed reliable by scholars, and he has a narration in Muslim. The hadith was previously mentioned at 13516.