Ruling on receiving a "non-working hours" salary without work

Question: I am an employee working in one of the government departments, and sometimes we are paid outside of working hours by our administration, without being assigned work outside of working hours, and without our presence at the administration. They consider it a reward for employees from time to time, knowing that the head of the administration is aware of it and approves of it. Please inform us, may Allah reward you with good, is it permissible to take this money? And if it is not permissible, how should I deal with the money I received in the past, knowing that I have already disposed of it? May Allah reward you with good.

Answer: If the situation is as you described, then it is a reprehensible act that is not permissible; rather, it is a form of betrayal. It is obligatory to return what you received through this means to the state treasury. If you are unable to do so, you must give it in charity to the poor Muslims and to charitable projects, along with repentance to Allah (Glorified and Exalted is He) and a sincere resolve not to return to that; because it is not permissible for a Muslim to take anything from the treasury of the Muslims except through the legal means that the state knows and approves of. And success is from Allah.