Someone appointed him to give one thousand Egyptian pounds to orphans; should he give it in pounds or riyals?
Question

I am Egyptian, and I travelled to Saudi. I have with me some money that one of my friends gave for orphans. Should I give the same numerical value in the local currency of the country, or should I give the equivalent value? I mean for example, if the amount is one thousand Egyptian pounds, should I give one thousand riyals or the equivalent of one thousand pounds in riyals?
Praise be to Allah.If the donor named a specific orphan or a specific country, then you must adhere to what he said to you, because the proxy should not deal with what was entrusted to him except in accordance with the instructions that he received only, and he has no right to do whatever he wishes.
Shaykh Ibn ‘Uthaymin (may Allah have mercy on him) said:
The proxy who was given instructions by the one who appointed him should only deal with what was entrusted to him in accordance with the instructions of the one who appointed him. If he can only act in accordance with the instructions of the one who appointed him, then he should not overstep the mark and do anything other than what he was instructed to do…
The basic principle is that the proxy should do what he was instructed to do. Therefore his actions must be in accordance with what he was instructed to do and he should not overstep the mark."(Ash-Sharh al-Mumti‘  9/350).
Undoubtedly the basic principle is that you should give the money that your friend gave you to the orphans of the country where you are. That is what may be concluded from his actions. It is the country where the currency mentioned is used. If he wanted you to give it to the orphans of a different country, he would have explained that to you, or he would have asked you to exchange the currency for the currency of the other country.
This is supported by the fact that it is known that the orphans and poor people of your country and that of your friend are more numerous and more deserving than those of the country to which you travelled. Does it make sense to transfer charity from the country of poor people to spend it in a country where most people are well off and have no need of that charity which, if you gave it to them in their currency, would be insignificant and of little value to them?
What appears to be the case is that it is not permissible for you to move it to that country except with the permission of your friend. The matter is easy: you can ask him about that, and if he gives you permission, you can go ahead [and give it to orphans in Saudi], otherwise you should send it back and spend it on orphans in your country and the country of your friend.
Whatever the case, if we assume that the owner of the money did not object to you spending it on orphans in the country to which you travelled, or he asked you to spend it there, and he gave you one thousand pounds, you only have to give the equivalent amount in the currency of the country where you are, and you do not have to give one thousand riyals.
And Allah knows best.