The Prophet ﷺ forbade selling the fruit of date palms until it ripens.We asked Anas, "What does ripening mean?"He replied, "It turns red and yellow. Tell me, if Allah prevents the fruit from maturing, on what basis would you take your brother's wealth?"
أن النبي ﷺ نهي عن بيع ثمر النخل حتى تزهو. فقلنا لأنس: ما زهوها؟ قال: تحمر، وتصفر، أرأيت إن منع الله الثمرة بم تستحل مال أخيك.
Bukhari related it in the Book of Sales (2208), and Muslim in the Book of Sharecropping (1555), both from Qutayba, who said, Ismail bin Jafar narrated to us, from Humayd, from Anas, who mentioned it. The wording given here is that of Muslim.