عَنْ أَنَسِ بْنِ مَالِكٍ رَضِيَ اللَّهُ عَنْهُ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ نَهَى عَنْ بَيْعِ الثَّمَرَةِ حَتَّى تَزْهُوَ وَعَنْ بَيْعِ الْعِنَبِ حَتَّى يَسْوَدَّ وَعَنْ بَيْعِ الْحَبِّ حَتَّى يَشْتَدَّ
It is narrated from Sayyiduna Anas (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him and his family) forbade selling fruit before it ripens, grapes before they turn black, and grain before it hardens.