Musnad Ahmad 33:1122

Hassan narrated to us, Ibn Lahi'ah narrated to us, Abu al-Zubayr narrated to us, from Jabir: That he heard the Messenger of Allah, peace and blessings of Allah be upon him, forbidding *al-khars* (estimating the yield of dates while still on the trees). He said: "Do you see, if the fruit were to perish, would any of you like to consume the wealth of his brother unjustly?"