Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) says that the Messenger of Allah (peace and blessings be upon him) forbade "al-muhaqalah (muhaqalah), al-muzabanah (muzabanah), al-mukhabarah (mukhabarah) and al-mu'awamah (mu'awamah)." One of them says: "Selling for years ahead and al-thunya (an exception) are also forbidden," and he granted a concession in al-araya (araya), that is, the fruit on the tree may be sold by estimate in exchange for dry dates, so that the owner can make use of the fresh fruit of the trees.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10618