Is there expiation for breaking a pledge not to work outside the scope of one's employment, and is the money earned from this work permissible or forbidden?

The employer is not entitled to stipulate that an employee should not work outside official working hours, because this condition contradicts human freedom and one's ownership of their own benefits, unless the second job leads to an inability to perform the duties of the first job. If his external work affects his work at the university, he must choose one of the two jobs, otherwise he would be betraying the trust. However, if he performs his work at the university properly and his external work does not affect it, then there is no blame upon him.