Tafsir of At-Taghabun 64:8

The fa (ف) in His saying—Exalted is He—"So believe" (fa-āminū) is mufṣiḥah (explanatory) of a condition that has been omitted due to its extreme obviousness; that is to say: If the matter is as has been described, then believe in Allah, whose affairs—Mighty and Majestic is He—you have heard what you have heard, and in His Messenger, Muhammad—may Allah bless him and grant him peace—and in the Light that We have sent down, which is the Qur’an. For indeed, by its inimitability, it is self-evident and makes evident that which is other than it, just as light is likewise.

The shift to the pronoun of majesty (the nūn of "We have sent down") serves to highlight the importance of the act of revelation, and therein lies the magnification of the status of the Qur’an.

"And Allah is All-Aware of what you do," regarding compliance with the command or the abandonment of it; meaning, He is Knower of its hidden aspects. It is also said: He is Knower of its realities.