Albert Barnes Commentary Psalms 98:1

"Oh sing unto Jehovah a new song; For he hath done marvellous things: His right hand, and his holy arm, hath wrought salvation for him." — Psalms 98:1 (ASV)

O sing to the Lord a new song - Compare Psalms 33:3; Psalms 96:1. For he has done marvelous things. These are things suited to excite wonder or to fill the mind with astonishment. See Psalms 77:14; Psalms 86:10.

His right hand - The instrument by which we execute any purpose. Compare Isaiah 59:16; Isaiah 63:5.

And his holy arm - The arm of his holiness; that is, his arm put forth in a righteous cause, or vindicating that which is right.

Has gotten him the victory - Literally, “has worked salvation for him”: for himself, or in his own cause. The victory—the salvation—was really in defense of his own government, in maintaining his own authority against those who set themselves in opposition to it.

What is here said may be applied to all that God does. It is really in his own cause, in order to maintain the principles of his own administration.