Is it permissible to say in supplication, "O Lord of lords"?

It is permissible for the supplicant to say in their supplication: "O Lord of lords," intending thereby to praise Allah, based on the hadith of Ibn Mas'ud which allows a person to choose whatever they wish from supplications and praises. This phrase does not imply acknowledging the lordship of anyone other than Allah; rather, it negates the lordship of all others, for the true and disposing Lord is Allah alone. And if "lords" is intended to mean people of authority or owners of slaves, there is also no issue, because their lordship is merely superficial, and they and their slaves are subject to the authority of Allah.