Messenger of Allah ﷺ forbade the sale of fruits till they are almost ripe. He was asked what is meant by 'are almost ripe.' He replied, "Till they become red." Messenger of Allah ﷺ further said, "If Allah spoiled the fruits, what right would one have to take the money of one's brother (i.e. other people)?"  

أَنَّ رَسُولَ اللَّهِ ﷺ نَهَى عَنْ بَيْعِ الثِّمَارِ حَتَّى تُزْهِيَ فَقِيلَ لَهُ وَمَا تُزْهِي قَالَ حَتَّى تَحْمَرَّ فَقَالَ أَرَأَيْتَ إِذَا مَنَعَ اللَّهُ الثَّمَرَةَ بِمَ يَأْخُذُ أَحَدُكُمْ مَالَ أَخِيهِ