I will set his hand also in the sea, &c.— i.e. "His empire shall extend from the Mediterranean sea to the rivers Euphrates and Tigris." See 2 Samuel 8:1 and Psalms 72:8.
Related Commentaries of Psalms 89:25
Psalms 89:25
25 I will set his hand also in the sea, and his right hand in the rivers.