Radak: Then they will recognize that Your throne was always established, i.e. before the world, and You created the world.

Malbim: Shamayim is called Kisei Hashem - "Hashem ba'Shamayim Hechin Kis'o" (103:19). This is the conduct of Ma'areches ha'Shamayim; based on it, He conducts the world according to fixed natural laws. He prepared His Kisei from the six days of creation.

Malbim: Even though Your Kisei, from the creation, conducts the world via nature (Ma'arachah), You do not conduct only according to it. You Yourself are in the world to conduct not via the Kisei, rather, miraculous conduct of Hashgachah that is attributed to You Yourself.