It is narrated from Sayyiduna Ibn Amr (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: "The seller and the buyer (the one who sells and the one who buys) have the option to cancel the transaction as long as they do not separate, except in the case where the matter of option has been settled. And it is not permissible for anyone to hastily separate from his companion out of fear that he might cancel the sale (terminate the transaction)."