Ruling on exchanging one currency for another during the transfer process

Question:
Regarding the work of transferring money via banks from the riyal to the Sudanese pound, this affects the Sudanese economy. What is your opinion, and what is the ruling on this?

Answer:
We are not aware of any harm in the transfer, if one transfers dollars to Sudan, or to a place other than Sudan, or the British pound, or otherwise, in the currency he wants and desires. However, it must be hand-to-hand; it is necessary that it be hand-to-hand. He takes possession of the currency he wants and then transfers it.
Some scholars have permitted this check because it constitutes taking possession. If this check is on a bank where the person has a balance, then taking possession of the check is taking possession of the money, because it stands in its place. It is not like a debt; it stands in its place because it is money. Wherever he goes with it, he obtains what is required. But if it is easy for him to take possession of his money himself and then transfer it, that is more complete.

Question: No, he transfers the Sudanese pound to dollars and keeps the dollars with him to sell them in Sudan, or in Egypt, what they call the black market, without the government's knowledge?

Answer: But he must take possession of them.

The student: He actually takes possession of them, but this harms the Sudanese economy, or the Egyptian economy, in the case of transferring it through a channel other than the bank?

Answer: We are not aware of any harm in this.