عَنِ ابْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُمَا أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ نَهَى عَنْ بَيْعِ النَّخْلِ حَتَّى يَزْهُوَ وَعَنِ السُّنْبُلِ حَتَّى يَبْيَضَّ وَيَأْمَنَ الْعَاهَةَ نَهَى الْبَائِعَ وَالْمُشْتَرِيَ
It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) forbade the sale of dates until they become ripe in color, and also forbade the sale of ears of grain until the grain becomes firm and safe from calamity. The Prophet (peace and blessings be upon him) forbade both the seller and the buyer.