Is paying money in Egyptian Pounds to one's family, then having it transferred back to him later in US Dollars, considered a form of Riba An-Nasi'ah (interest due to delay)?

If the amount paid is a debt owed by your expatriate brother, it is permissible to repay it in US dollars at the exchange rate on the day of repayment, provided you agree. However, if there was a prior agreement to repay the Egyptian pound with US dollars, it is not permissible because it combines a loan and a sale, and is considered deferred currency exchange. It is permissible for the creditor and debtor to agree on the day of repayment to settle the debt in a currency different from the original debt currency at its exchange rate on the day of repayment. It is not permissible to agree to record the debt as equivalent to the value of gold or another currency owed by the debtor.