“Eternity is the sun
mixed
with the sea”

Source: Pale Fire

A Sea Child, reported in Bartlett's Familiar Quotations, 10th ed. (1919).

"The Dirge of the Sea" (April 1891)
Context: Years! Years, ye shall mix with me!
Ye shall grow a part
Of the laughing Sea;
Of the moaning heart
Of the glittered wave
Of the sun-gleam's dart
In the ocean-grave. Fair, cold, and faithless wert thou, my own!
For that I love
Thy heart of stone!
From the heights above
To the depths below,
Where dread things move, There is naught can show
A life so trustless! Proud be thy crown!
Ruthless, like none, save the Sea, alone!

Source: Nausea

Source: Terre des Hommes (1939), Ch. I : The Craft
Context: "Navigating by the compass in a sea of clouds over Spain is all very well, it is very dashing, but—"
And I was struck by the graphic image:
"But you want to remember that below the sea of clouds lies eternity."
And suddenly that tranquil cloud-world, that world so harmless and simple that one sees below on rising out of the clouds, took on in my eyes a new quality. That peaceful world became a pitfall. I imagined the immense white pitfall spread beneath me. Below it reigned not what one might think — not the agitation of men, not the living tumult and bustle of cities, but a silence even more absolute than in the clouds, a peace even more final. This viscous whiteness became in my mind the frontier between the real and the unreal, between the known and the unknowable. Already I was beginning to realize that a spectacle has no meaning except it be seen through the glass of a culture, a civilization, a craft. Mountaineers too know the sea of clouds, yet it does not seem to them the fabulous curtain it is to me.

From, On Loving of God, Paul Halsall trans., Ch. 11