Sunan an-Nasa'i, Volume 6, Book 51, Hadith 5632 (DarusSalam) ⓘ
It was narrated from Anas bin Malik that: The Messenger of Allah [SAW] forbade soaking (fruits) in Ad-Dubba' (gourds) and Al-Muzaffat.
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنِ ابْنِ شِهَابٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّهُ أَخْبَرَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَهَى عَنِ الدُّبَّاءِ وَالْمُزَفَّتِ أَنْ يُنْبَذَ فِيهِمَا .
also referenced under: Hadith 5629 (Reference) & Book 51, Hadith 91 (In-Book)