The ruling on currency exchange and whether riba (usury or interest) applies to it

Question:
He says: Honorable Shaykh, I am asking about sarf (currency exchange), meaning from one currency to another, for example. Does this count as riba (usury or interest), and that in the economic situation of every country?

Answer:
Yes, exchanging currency for currency involves riba, either riba al-fadl (usury of excess in a like-for-like exchange) or riba al-nasi'ah (usury of deferment). If money is sold for its own kind of money, it involves both riba al-fadl and riba al-nasi'ah. In this case, equality in amount and immediate exchange in the meeting are required, just as if one sold a Saudi riyal for a Saudi riyal. Here the kind is the same, the operative cause is the same, so immediate possession is necessary, which is the exchange, and equality in amount is necessary.
As for when the types differ, such as selling Saudi riyals for US dollars, in this case, differential exchange is permissible, but deferred payment is forbidden. The Messenger of Allah (peace and blessings be upon him) said: . If it is riba al-nasi'ah (usury of deferment), it is forbidden whether the type is the same or different among the currencies exchanged with one another. As for riba al-fadl (usury of excess in a like-for-like exchange), it only occurs when the type is the same. Yes.

The presenter:
May Allah reward you,