The Ruling on Riba in Paper Currency

Question:
Does paper currency fall under the ruling of riba (usury or interest) if an increase is taken, for example, one hundred for one hundred and ten after a month, or does it not fall under it because their prices change over the years?

Answer:
No, my brothers. Paper money takes the place of gold and silver, so the ruling of gold and silver applies to it. Therefore, an increase is not permissible between them if they are of the same type, such as one Saudi riyal for two Saudi riyals; this is not permissible. Or a Saudi riyal payable now for a Saudi riyal payable later; this is not permissible. However, if the type differs, such as selling a Saudi riyal for an Egyptian pound, or the currency of another country where the type differs, then an increase is permissible, but a delay is not permissible. If these types differ, sell them however you wish, provided it is hand-to-hand. Yes.