Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) said that the Messenger of Allah (peace and blessings be upon him) "forbade muhaqalah, muzabanah and mukhabarah, and also prohibited selling fruit before it ripens, and (that) it be sold only for dinars or dirhams, except the 'araya."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10653