The Messenger of Allah forbade soaking raisins and Al-Busr together, and he forbade soaking Al-Busr and ripe dates together.
Sunan an-Nasa'i Book 51, Hadith 23
← Previous Hadith The Prophet said: "Do not soak Az-Zahuw and ripe dates, and do not soak ripe dates and raisins together."

Sunan an-Nasa'i Book 51, Hadith 22 Next Hadith → "The Messenger of Allah forbade us to soak two things together when one is more potent than the other. I asked him about Fadikh (a drink made from fresh dates cut open) and he forbade it. He disliked the extra bit on Al-Busr, fearing that that might make it two things, so we used to cut it off."

Sunan an-Nasa'i Book 51, Hadith 24