Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates from Sayyiduna Zayd bin Thabit (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) forbade muhaqalah (selling the produce of a field by estimate) and muzabanah.
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 4763