Does the permissibility of money differ based on the nature of jobs?

The effort expended in the work does not affect the permissibility of the salary. What is considered is the performance of the work agreed upon in the contract, whether it is light or arduous. The salary of one who performs a permissible job is lawful for him, based on the Almighty's saying: "O you who have believed, fulfill [all] contracts." The فقهاء (jurists) have mentioned that the wage is due to the worker and is good for him even if no work is assigned to him.