The Messenger of Allah ﷺ forbade muzabanah, which is selling the fruit still on the tops of the palm trees for a specified measure of dried dates, on the terms, "If it turns out to be more, the gain is mine, and if it turns out to be less, the loss is mine."
و حدثناه أبو الربيع وأبو كامل قالا حدثنا حماد حدثنا أيوب بهذا الإسناد نحوه