What is the ruling on giving a discount that is not apparent on the invoice as a commission to a sales representative, given the stability of prices and discount rates, and the expectation of a significant decrease in sales if these commissions are prohibited, and what is the legitimate option in such a case?

The purchasing agent acts as a representative for the one who sent him, and he must work for the benefit of his client to obtain the lowest prices and the best goods in exchange for his wages. It is not permissible for him to take a commission from the seller for himself or to falsify invoices with an unreal price, nor is it permissible for the seller to cooperate with him in that. All of this falls under cheating and cooperating in forbidden sin, even if it is a common market practice, because if custom contradicts Islamic law, it must be abandoned. The agent does not have the right to demand gifts or commissions, for the Prophet, peace and blessings be upon him, said: "Gifts to officials are ill-gotten gains." Companies and agents must fear Allah and repent from these practices.