Maliks Muwatta Book 31, Hadith Number 12.

Section : Prohibition against Selling Fruit until It starts to Ripen.

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).”