What is the ruling on someone who changed their place of residence due to a circumstance, then wished to return to the first place of residence for financial gain? And is such a change permissible for them?

A person's relocation from one country to another for material gain is permissible under Islamic law, such as someone who travels to a country and then returns to it due to the availability of a job opportunity or other reasons. Similarly, one who moves to a country to benefit from the revenue of an endowment (waqf) where the endower stipulated that it be spent on those residing therein [is also permissible]. The important thing is that there should be no circumvention through a false stratagem to obtain material benefit without a legitimate right, based on the Almighty's saying: "Do not consume your property among yourselves through falsehood."