It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that a man made a sale by salam (advance payment) for dates from another man’s tree, but that year the tree bore no fruit. When he wanted to take his money back, the seller refused. The man came to the Prophet Muhammad (peace and blessings be upon him). The Prophet (peace and blessings be upon him) asked the owner of the trees,“Did your trees not bear fruit?”He replied,“No.”The Prophet (peace and blessings be upon him) said,“Then why are you withholding his money?”So he returned his money to him. After that, the Prophet (peace and blessings be upon him) forbade making a sale by salam until the fruit ripens.