Sayyiduna Abdullah bin Amr (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings be upon him) said: "The buyer and the seller have the option (to cancel the transaction) as long as they have not separated from each other, unless it is a sale with a stipulated option (i.e., the option to annul the sale has been given). And it is not permissible to separate quickly out of fear that the transaction will be returned."