It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) forbade the sale of Muzabana, which is that a person sells the produce of his land for a known weight on the condition that if the produce turns out to be more, he will not get anything extra, and if the produce is less than the weight, he will be responsible for the loss. Zaid bin Thabit (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) permitted the sale of dates on the tree (in exchange for an estimated amount of dry or fresh dates).