What should I do to purify my money, seeing that I accepted a commission from a contractor in exchange for giving him some work, and I have repented to Allah, but I have not returned the money to the company for fear of legal accountability?

If the contractor gives money to the supervisor to gain his favor in assigning some work to him, this money is a forbidden bribe and should not be returned to the contractor; rather, it should be spent on charitable causes. The Permanent Committee has stated that taking this amount is unlawful, is not considered a gift, and must be spent on charitable causes, and should not be returned to the contractor.