Is my learning the tasks of a freelance graphic designer and performing part of his work – which I correct and proofread – considered cutting off his livelihood or sinful, given my aim to increase my limited income? And if I offer my services to the company, must I adhere to the designer's cost, or is it permissible for me to offer a discount as a permanent employee?

It is forbidden for a Muslim to sell over the sale of his brother or to rent over his rent, according to the saying of the Prophet, peace and blessings be upon him: "None of you should sell over the sale of his brother." And renting is a sale of usufructs.

This prohibition includes the period of option and after the contract becomes binding, because that may lead to regret and resentment.

Some scholars have appended to this the hiring of a worker whom the renter has relied upon to hire after the expiration of his contract, due to the harm and damage it causes him.

Therefore, if the company has relied on dealing with a person who performs work for it and is not an employee of it, it is not permissible for you to apply to take his place; unless the work has increased and exceeded his capacity, or if the company wishes for another person to perform some of the work.