If you borrow ৫০ 50 from a person or organization for five years, you do not have to repay anything other than this amount in this currency. Even if the price of the currency falls; As long as transactions in this currency continue.
It has already been mentioned in Question No. 12541 that it is haraam to pay extra in repayment of loan due to depreciation of currency and it is considered as interest. This is the opinion of Jamhur Alem.
A person who has taken a loan in one currency and agreed to repay it in another currency, is engaged in interest. Because the nature of this transaction is to sell one class of cash to another class of currency. It is forbidden. This is also a kind of interest. Which is called ‘Riba Nasia’.
But the borrower can negotiate with the lender to repay the loan in another currency while repaying the loan.
In the above example you will have to pay ৫০ 50 when five years have elapsed. However, on the day of repayment, you can negotiate with the lender that you will repay him in other currencies, such as dollars. However, the condition is that it must be at the exchange rate on the day of payment.
On the other hand, taking a loan on which there is a profit of inflation: It has already been mentioned that taking extra in the face of inflation is haram and that is interest. So it will not be permissible for you to take this loan. Because the Prophet (peace and blessings of Allaah be upon him) cursed the usurer, the usurer, the usurer, the usurer, and said: They are all equal. [Saheeh Muslim (1596)]