John Gill Bible Commentary

I will set his hand also in the sea,.... Which is expressive not of his dominion over the sea, and of his power and authority over all things in it, which: he has by right of creation, and as Mediator, Psa 8:5, of which there were instances in the days of his flesh, Mat 8:26, but of his kingdom taking place in, and of his government over the inhabitants of the isles of the sea; and so the Targum, "I will set or place his government in the provinces of the sea;'' and which has been remarkably accomplished in our isles, where his Gospel has been preached, his kingdom set up, and he has had a race of subjects, and a seed, to serve him for many years: and his right hand in the rivers: or, as the Targum, "the power of his right hand in those that dwell by rivers;'' meaning such that dwell upon the continent, afar off from the sea, and whose countries are watered by rivers: so that both phrases denote the extent of Christ's kingdom in the continent, and in the islands of the sea; signifying, that it should reach everywhere, and be from sea to sea, and from the river to the ends of the earth, Psa 72:8. Compare with this Rev 10:1. Aben Ezra interprets it of David's prevailing over those that go in ships in the sea, and in rivers.