From Sahih Bukhari (Hadith 2208):
Narrated Humaid:Anas said, "The Prophet (ﷺ) forbade the selling of dates till they were almost ripe." We asked Anas, "What does 'almost ripe' mean?" He replied, "They get red and yellow. The Prophet (ﷺ) added, 'If Allah destroyed the fruits present on the trees, what right would the seller have to take the money of his brother (somebody else)?
Reference: Bukhari 2208