Thy life to thy neighbor's creed has lent.
All are needed by each one;
Nothing is fair or good alone.
I thought the sparrow's note from heaven,
Singing at dawn on the alder bough;
I brought him home, in his nest, at even;
He sings the song, but it pleases not now,
For I did not bring home the river and sky; —
He sang to my ear, — they sang to my eye.
The delicate shells lay on the shore;
The bubbles of the latest wave
Fresh pearls to their enamel gave;
And the bellowing of the savage sea
Greeted their safe escape to me.
I wiped away the weeds and foam,
I fetched my sea-born treasures home;
But the poor, unsightly, noisome things
If you’ve ever been to the ocean, you know you hear the strength of the tides coming in. 
 Emerson uses a contrast between this  savage  sea and these delicate pearls to draw attention.