Abdul Malik bin Ubaidah narrates: I was present with Abu Ubaidah bin Abdullah when two men came to him. They made a transaction for something. One of them said: "I have bought this item for such and such amount." The other said: "I have sold it for such and such amount." So, Sayyiduna Abu Ubaidah said: A similar situation was presented before Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), and he informed that I was present with the Prophet Muhammad (peace be upon him) when such a matter was brought before him. The Prophet (peace be upon him) instructed regarding the seller: "He should be made to swear an oath, then after that, the buyer will have the choice—if he wishes, he may take the item according to the seller's statement, and if he wishes, he may leave it."