What is the ruling on taking a commission for mediating in bringing workers to a construction and building company, and is the mediator considered a partner in any injustice that may befall the workers?

It is permissible to hire workers for lawful tasks and to act as an intermediary in this, whether for a fee or without, provided the intermediary does not know that the employer will use the worker for unlawful purposes or oppress him. If the intermediary does not know, and then the employer mistreats the worker, the sin is on the oppressor, not on the intermediary. It is permissible for the intermediary to take a commission from both parties if he is not an agent for either, according to the agreement or custom.