the messenger of Allah forbade Muzabana, and Muzabanah means selling fresh dates still on tree for dried dates by measure, and selling fresh grapes for raisins by measure.
أَنَّ رَسُولَ اللَّهِ ﷺ نَهَى عَنِ الْمُزَابَنَةِ وَالْمُزَابَنَةُ بَيْعُ الثَّمَرِ بِالتَّمْرِ كَيْلاً وَبَيْعُ الْكَرْمِ بِالزَّبِيبِ كَيْلاً