Hajjaj bin Artah حجاج بن أرطاة · The Chapters on Business Transactions

"The Messenger of Allah (ﷺ) forbade the Muzabanah. The Muzdbanah means when a man sells the dates of his grove when they are still on the tree, for a measure of dty dates; or, if it is grapes, he sells them when they are still on the vine, for a measure of raisins; or if it is a crop, he sells it for food, estimating the amount (of the crop in the field). He forbade all of these things."