What is the ruling on saying: "So you know you are dealing with a professional" when speaking of the Creator's magnificence?

The names and attributes of Allah Almighty are tawqifiyyah (restricted to what is revealed), but the باب الإخبار عنه (realm of informing about Him) is broader. Therefore, it is permissible to inform about Him with terms not explicitly mentioned if the meaning is sound, such as "the Thing" (الشيء) and "the Existent" (الموجود).

However, describing Allah as "professional" (محترف) in the sense of mastery involves disrespect, because ihtiraf (professionalism) inherently implies acquisition, effort, skill, and training. These meanings are unfitting for Allah, who creates without toil by His word: "Be, and it is." Thus, it is impermissible to describe Allah with this term due to its inclusion of a meaning that does not befit Him.