Is it permissible for the seller to delay giving a person an amount after the exchange (i.e., after the transaction or payment has been made)?

The exchange of possession must take place in the same session when selling one currency for another, based on the Prophet's (peace be upon him) saying: "If these types differ, then sell as you wish, provided it is hand to hand." Therefore, it is not permissible to delay the receipt of either or both عوضين (countervalues) or any part thereof beyond the contract session in transactions where immediate possession is a condition, because this falls under Riba al-Nasi'ah (interest due to delay).