Musnad Abu Ya'la al-Mawsili 153:197

Al-Mu'alla ibn Mahdi narrated to us, Abu 'Awanah narrated to us, from Zayd, who said: I heard Ibn 'Umar, and a man asked him about the fruit. He said: The Messenger of Allah (may Allah bless him and grant him peace) forbade the selling of fruit until its ripeness becomes apparent.