Is it permissible to perform a special extra job during official work hours at the institution, given that free time allows for it, there is no negligence in the primary work, and none of the institution's resources are used for the extra job?

The employee is a private hireling, and he must dedicate his services to his employer throughout the time agreed upon in the contract, as the Prophet, peace and blessings be upon him, said: "Muslims are bound by their conditions." He is not allowed to perform work for anyone other than his employer during his free time unless he has permission, because he receives wages for this time even if no work is assigned to him. The private hireling is entitled to wages by dedicating himself for the duration, even if he does not perform work.