كتاب البيوع
21  
The Book of Transactions
(14)
Chapter: The prohibition of selling fresh dates in exchange for dry dates except in the case of 'Araya
(14)
باب تَحْرِيمِ بَيْعِ الرُّطَبِ بِالتَّمْرِ إِلاَّ فِي الْعَرَايَا ‏‏
Sahih Muslim 1542 a

Ibn Umar (Allah be pleased them) reported Allah's Messenger (ﷺ) having forbidden Muzabana, and Muzabana implies the selling of fresh dates for dry dates by measuring them out and the selling of raisins by measure for grapes.

حَدَّثَنَا يَحْيَى بْنُ يَحْيَى التَّمِيمِيُّ، قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَهَى عَنِ الْمُزَابَنَةِ وَالْمُزَابَنَةُ بَيْعُ الثَّمَرِ بِالتَّمْرِ كَيْلاً وَبَيْعُ الْكَرْمِ بِالزَّبِيبِ كَيْلاً ‏.‏
Reference : Sahih Muslim 1542a
In-book reference : Book 21, Hadith 92
USC-MSA web (English) reference : Book 10, Hadith 3693
  (deprecated numbering scheme)