the Messenger of Allah forbade selling dates in the trees before they ripen or selling ears of corn before the grains become visible and there is no fear of blight. He forbade that to the seller ad the buyer. ,"  

أَنَّ رَسُولَ اللَّهِ ﷺ نَهَى عَنْ بَيْعِ النَّخْلَةِ حَتَّى تَزْهُوَ وَعَنِ السُّنْبُلِ حَتَّى يَبْيَضَّ وَيَأْمَنَ الْعَاهَةَ نَهَى الْبَائِعَ وَالْمُشْتَرِيَ  

a man form among the companions of the Prophet told him, he said: "O Messenger of Allah we cannot buy Saihani dates or 'idhq dates for the same amount of mixed dates (which are of inferior quality). Should we increase (the amount we give in payment for the better quality dates)?" The messenger of Allah said: "Sell them for silver them buy with it"  

أَنَّ رَجُلاً مِنْ أَصْحَابِ النَّبِيِّ ﷺ أَخْبَرَهُ قَالَ يَا رَسُولَ اللَّهِ إِنَّا لاَ نَجِدُ الصَّيْحَانِيَّ وَلاَ الْعِذْقَ بِجَمْعِ التَّمْرِ حَتَّى نَزِيدَهُمْ فَقَالَ رَسُولُ اللَّهِ ﷺ بِعْهُ بِالْوَرِقِ ثُمَّ اشْتَرِ بِهِ