What is the ruling on the commission I took from the contractor, whom I brought to a client outside my duties, knowing that my office will supervise the implementation? And is it obligatory to inform the owner of the office about this? And what should I do if he wants to take it?

For you to be permitted to take a commission for a certain work, it is a condition that the work is not part of your contractual job duties, nor during your official working hours, and that you do not supervise its execution, in order to avoid the accusation of favoritism. If these conditions are met, then it is permissible for you to take the commission even without the knowledge of the office owner; otherwise, it is not permissible. As for the office, it is not permissible for it to take a commission from the contractor if it will be supervising the execution.