Musnad Abu Ya'la al-Mawsili 154:89

Khalaf ibn Hisham narrated to us, Abu 'Awanah narrated to us, from Zayd ibn Jubayr, he said: I heard a man asking Ibn 'Umar about the sale of fruit. He said: The Messenger of Allah (may Allah bless him and grant him peace) forbade the sale of fruit until its ripeness becomes apparent.