What is the ruling on receiving payment for overtime hours that an employee is assigned to work in a committee outside his department?

If the company allows the employee to combine their primary work with their delegated work during the same working hours, with the delegated hours counted as overtime, then there is no objection to this.

However, if the company does not permit this, and this is an action taken by the manager, then it is not permissible for the employee to accept it. This is because it constitutes a breach of trust and may lead to favoritism. The fundamental principle is that a person should not work for another entity during working hours or be assigned work other than their agreed-upon duties, except with the permission of the entity they work for.