Sheikh Sâmî al-Suwaylim, member of the Islamic Advisory Board of al-Rajhi Bank
A loan in Islamic finance is strictly a non-profit transaction. Any stipulated addition to the loan makes it a for-profit transaction, and thus one that contains interest (ribâ).
Accordingly, it is normal in a non-profit transaction that one party is sacrificing for the benefit of the other, whether due to inflation (where the loss would be born by the lender), deflation (where the loss would be born by the borrower), or otherwise.
Islamic law only allows a profit to be made in a transaction that creates value. This means that the transaction must be value-creating in and of itself, and therefore must involve the exchange of real goods and services.
And Allah knows best.
Source: Islam Today