Albert Barnes Commentary Psalms 89:13

"Thou hast a mighty arm; Strong is thy hand, and high is thy right hand." — Psalms 89:13 (ASV)

Thou hast a mighty arm - Margin, as in Hebrew, “an arm with might.” That is, You have great power - the arm being the instrument by which we accomplish our purposes.

Strong is thy hand - The hand, too, is an instrument by which we execute our plans. Hence, God is so often represented as having delivered his people with a strong hand.

And high is thy right hand - It is by the right hand particularly that we carry out our purposes. We lift it high when we are about to strike with force. All this is expressive of the divine omnipotence.