John Gill Commentary Psalms 65:7

"Who stilleth the roaring of the seas, The roaring of their waves, And the tumult of the peoples." — Psalms 65:7 (ASV)

Which stilleth the noise of the seas, the noise of their
waves
By a word speaking; as our Lord did when here on earth, and which was a proof and evidence of his eternal power and Godhead. These figurative expressions are interpreted by the next clause;

and the tumult of the people :
of wicked men, who foam and rage against the people of God, and are like a troubled sea that cannot rest; but God can say to these proud waters, which threaten to go over their souls, Peace, be still; he can stop their opposition, quell their insurrections, restrain their wrath, and make them peaceable and quiet; wherefore the saints have no reason to be afraid of them, (Psalms 46:2Psalms 46:3) (76:10) (124:1-5) .