Tafsir of At-Takweer 81:19

{Indeed, it is the word of a noble messenger} The pronoun refers to the Qur’an. The "noble messenger" is Gabriel—peace be upon him.

{Possessor of power} Similar to the Almighty’s saying: "Mighty in power, possessor of soundness" (An-Najm: 5-6).

{With the Possessor of the Throne} Since the status of a place corresponds to the status of the one who occupies it, He said: "With the Possessor of the Throne," to indicate the greatness of his rank and position.

{Then} This is a reference to the aforementioned station—meaning: "With the Possessor of the Throne"—indicating that he is with Allah, obeyed among the angels who are brought near; they act upon his command and defer to his judgment.

It has also been recited as "Thamma" (There), to emphasize the [trustworthiness] mentioned, and to clarify that it is the greatest of his enumerated attributes.