Is the commission received by a tour guide for selling goods to foreigners at a higher price unlawful, and how can this money be purified if it is?

To purify money earned from a forbidden commission, it should be disbursed to the poor and needy or for public welfare, with the intention of disposing of it because it is unlawful. Working in the tourism sector, as it currently stands, is impermissible. It is advisable to leave this forbidden work and seek another. If a person insists on continuing unlawful work after the evidence has been made clear, then he must be abandoned.