Muwatta Malik, Book 31, Hadith 12 (USC-MSA) ⓘ

Yahya related to me from Malik from Abu'r-Rijal Muhammad ibn Abd ar-Rahman ibn Haritha from his mother, Amra bint Abd ar-Rahman that the Messenger of Allah, may Allah bless him and grant him peace, forbade selling fruit until it was clear of blight. Malik said, "Selling fruit before it has begun to ripen is an uncertain transaction (gharar)."

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ أَبِي الرِّجَالِ، مُحَمَّدِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ حَارِثَةَ عَنْ أُمِّهِ، عَمْرَةَ بِنْتِ عَبْدِ الرَّحْمَنِ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَهَى عَنْ بَيْعِ الثِّمَارِ حَتَّى تَنْجُوَ مِنَ الْعَاهَةِ ‏.‏ قَالَ مَالِكٌ وَبَيْعُ الثِّمَارِ قَبْلَ أَنْ يَبْدُوَ صَلاَحُهَا مِنْ بَيْعِ الْغَرَرِ ‏.‏