Is the buyer entitled to annul the sale after agreement in the session and the departure of both parties, and before the handover of the price or the commodity?

If the sale has been concluded and the two parties have separated, the sale becomes binding, and neither party has the right to annul it except if there is a reason for an option, such as a defect or a significant discrepancy (ghabn), or with the other party's consent. If the sale is for a specific car, it is considered a binding sale even if the price has not been collected or the car delivered. However, if the sale is for an unspecified car (in ذمة, meaning generally described without specific identification), this sale is invalid, and it is a condition that the price or the car be taken possession of at the contract session. If the buyer regrets the purchase and there is no reason for an option, he can invite the seller to mutually rescind the contract (iqalah), and it is recommended for the seller to accept this. If there is a significant discrepancy (ghabn) in the price, the buyer has the option to either annul the sale or complete it. Ghabn is usually determined based on the custom of merchants, and some jurists have defined it as one-third or more of the price. The majority of jurists hold that the option of ghabn is limited to cases where there is deception (taghrir), such as intercepting incoming caravans (talaqqi al-rukban), bidding up prices without intention to buy (najash), or dealing with an unsuspicious person who is ignorant of prices (mustarsil). As for someone who has experience or was defrauded due to his haste, he has no option. The Malikis, in one view, hold that the option of ghabn is established for anyone who has been defrauded by one-third or more if he was ignorant of the value, provided that he demands the annulment before the lapse of one year. Therefore, if the difference between the price and the market price is significant, and the seller has deceived the buyer, or the buyer was ignorant of the value (according to the Maliki view), he has the option. If there is no ghabn or defect, the sale is binding, and the buyer does not have the right to annul it except with the seller's consent.