Adam Clarke on Psalms 93:1

The Lord reigneth - He continues to govern every thing he has created; and he is every way qualified to govern all things, for he is clothed with majesty and with strength - dominion is his, and he has supreme power to exercise it; and he has so established the world that nothing can be driven out of order; all is ruled by him. Nature is his agent: or rather, nature is the sum of the laws of his government; the operations carried on by the Divine energy, and the effects resulting from those operations.

He hath girded himself - The girding with strength refers to the girding in order to strengthen the loins, arms, knees, etc. When a Hindoo is about to set off on a journey, to lift a burden, or to do something that requires exertion, he binds firmly his loose upper garment round his loins - Ward.