Messenger of Allah ﷺ forbade the sale of fruits till their benefit is evident. He forbade both the seller and the buyer (such sale).  

أَنَّ رَسُولَ اللَّهِ ﷺ نَهَى عَنْ بَيْعِ الثِّمَارِ حَتَّى يَبْدُوَ صَلاَحُهَا نَهَى الْبَائِعَ وَالْمُبْتَاعَ  

The Prophet ﷺ forbade the selling of fruits unless they get ripe, and none of them should be sold except for Dinar or Dirham (i.e. money), except the 'Araya trees (the dates of which could be sold for dates).  

نَهَى النَّبِيُّ ﷺ عَنْ بَيْعِ الثَّمَرِ حَتَّى يَطِيبَ وَلاَ يُبَاعُ شَىْءٌ مِنْهُ إِلاَّ بِالدِّينَارِ وَالدِّرْهَمِ إِلاَّ الْعَرَايَا  

I asked Ibn ʿUmar about Salam for dates. Ibn ʿUmar replied, "The Prophet ﷺ forbade the sale (the fruits) of date-palms until they were fit for eating and also forbade the sale of silver for gold on credit." I also asked Ibn ʿAbbas about it. Ibn ʿAbbas replied, "The Prophet ﷺ forbade the sale of dates till they were fit for eating, and could be weighed." I asked him, "What is to be weighed (as the dates are on the trees)?" A man sitting by Ibn ʿAbbas said, "It means till they are cut and stored."  

نَهَى النَّبِيُّ ﷺ عَنْ بَيْعِ الثَّمَرِ حَتَّى يَصْلُحَ وَنَهَى عَنِ الْوَرِقِ بِالذَّهَبِ نَسَاءً بِنَاجِزٍ وَسَأَلْتُ ابْنَ عَبَّاسٍ فَقَالَ نَهَى النَّبِيُّ ﷺ عَنْ بَيْعِ النَّخْلِ حَتَّى يَأْكُلَ أَوْ يُؤْكَلَ وَحَتَّى يُوزَنَ قُلْتُ وَمَا يُوزَنُ قَالَ رَجُلٌ عِنْدَهُ حَتَّى يُحْرَزَ