Is it permissible to lend a sum of money on condition that it be returned in dollars at an agreed-upon rate lower than the market rate at the time of lending?

It is not permissible to agree, at the time of contracting a loan, to repay it in another currency, because it involves Riba An-Nasi'ah (interest due to delay), and because it is a deferred exchange which requires immediate possession. However, it is permissible for the lender and borrower to agree, at the time of repaying the loan, to repay it in another currency at the exchange rate on the day of repayment, not the day of the loan. This was stated in a resolution by the Islamic Fiqh Academy. Likewise, it is not permissible to record a debt in a specific currency equivalent to its value in gold or another currency, on the basis that the debtor is obliged to repay the debt in gold or the other agreed-upon currency.