I will set his hand also in the sea - This was literally fulfilled in David. Hand signifies power or authority; he set his hand on the sea in conquering the Philistines, and extending his empire along the coast of the Mediterranean Sea, from Tyre to Pelusium. All the coasts of the Red Sea, the Persian Gulf, and the Arabic Ocean, might be said to have been under his government, for they all paid tribute to him or his son Solomon.
His right hand in the rivers - First, the Euphrates: he subjected all Syria, and even a part of Mesopotamia; 2 Samuel 8:3; 1 Chronicles 18:3. He also took Damascus, and consequently had his hand or authority over the river Chrysorrhoes, or Baraddi; and in his conquest of all Syria his hand must have been on the Orontes and other rivers in that region. But if this be considered as referring to the typical David, we see that He was never conquered; he never lost a battle; the hosts of hell pursued him in vain. Satan was discomfited, and all his enemies bruised under his feet. Even over death he triumphed; and as to his dominion, it has spread and is spreading over all the isles of the sea, and the continents of the world.
I will set his hand also in the sea - His dominion shall extend from the sea on the one hand to the rivers on the other. The sea here evidently refers to the Mediterranean; and the rivers to the great rivers on the east - the Tigris and Euphrates. These were the promised boundaries of the land. Genesis 15:18. David secured a conquest over all these territories, and united all under his scepter, thus securing the accomplishment of the promise made to Abraham. See the notes at Psalm 60:1-12.
“I have sworn unto David My servant ... with whom My hand shall be established: Mine arm also shall strengthen him.... My faithfulness and My mercy shall be with him: and in My name shall his horn be exalted. I will set his hand also in the sea, and his right hand in the rivers. He shall cry unto Me, Thou art my Father, my God, and the Rock of my salvation. Also I will make him My first-born, higher than the kings of the earth. My mercy will I keep for him forevermore, and My covenant shall stand fast with him.” Psalm 89:3-28. PP 755.1
“His seed also will I make to endure forever,
And his throne as the days of heaven.” Psalm 89:29. PP 755.2
“He shall judge the poor of the people,
He shall save the children of the needy,
And shall break in pieces the oppressor.
They shall fear thee while the sun endureth,
And so long as the moon, throughout all generations....
In his days shall the righteous flourish;
And abundance of peace, till the moon be no more.
He shall have dominion also from sea to sea,
And from the river unto the ends of the earth.”
“His name shall endure forever:
His name shall be continued as long as the sun:
And men shall be blessed in him:
All nations shall call him blessed.” PP 755.3