Qasim bin Abdur Rahman narrates from his father, from his grandfather (Sayyiduna Abdullah bin Mas'ud, may Allah be pleased with him), that the Prophet Muhammad (peace and blessings be upon him) said: "When there is a dispute between the two parties involved in a transaction regarding the deal, and the goods are still present in their original condition and have not perished, then the statement of the seller will be considered valid, or both of them will annul the transaction."