“There is a silence where hath been no sound,
There is a silence where no sound may be,—
In the cold grave, under the deep, deep sea,
Or in the wide desert where no life is found.”

The Vow of the Peacock (1835)

Ash-Wednesday (1930)
Context: If the lost word is lost, if the spent word is spent
If the unheard, unspoken
Word is unspoken, unheard;
Still is the unspoken word, the Word unheard,
The Word without a word, the Word within
The world and for the world;
And the light shone in darkness and
Against the Word the unstilled world still whirled
About the centre of the silent Word. O my people, what have I done unto thee. Where shall the word be found, where will the word
Resound? Not here, there is not enough silence

Source: Kafka on the Shore

1830s, Sir Walter Scott (1838)

Alta vendetta
D'alto silenzio è figlia.
La Congiura de' Pazzi, I, 1; reported in Hoyt's New Cyclopedia Of Practical Quotations (1922), p. 707.

Vol. II, p. 30
1980s, Letters to the Schools (1981, 1985)
Context: Attention involves seeing and hearing. We hear not only with our ears but also we are sensitive to the tones, the voice, to the implication of words, to hear without interference, to capture instantly the depth of a sound. Sound plays an extraordinary part in our lives: the sound of thunder, a flute playing in the distance, the unheard sound of the universe; the sound of silence, the sound of one’s own heart beating; the sound of a bird and the noise of a man walking on the pavement; the waterfall. The universe is filled with sound. This sound has its own silence; all living things are involved in this sound of silence. To be attentive is to hear this silence and move with it.

Letter to his fiancée Lee, (31 July 1978), published in Gerald Durrell: An Authorized Biography by Douglas Botting (1999)
Context: I have seen a thousand sunsets and sunrises, on land where it floods forest and mountains with honey coloured light, at sea where it rises and sets like a blood orange in a multicoloured nest of cloud, slipping in and out of the vast ocean. I have seen a thousand moons: harvest moons like gold coins, winter moons as white as ice chips, new moons like baby swans’ feathers.
I have seen seas as smooth as if painted, coloured like shot silk or blue as a kingfisher or transparent as glass or black and crumpled with foam, moving ponderously and murderously. … I have known silence: the cold earthy silence at the bottom of a newly dug well; the implacable stony silence of a deep cave; the hot, drugged midday silence when everything is hypnotised and stilled into silence by the eye of the sun; the silence when great music ends.
I have heard summer cicadas cry so that the sound seems stitched into your bones. … I have seen hummingbirds flashing like opals round a tree of scarlet blooms, humming like a top. I have seen flying fish, skittering like quicksilver across the blue waves, drawing silver lines on the surface with their tails. I have seen Spoonbills fling home to roost like a scarlet banner across the sky. I have seen Whales, black as tar, cushioned on a cornflower blue sea, creating a Versailles of fountain with their breath. I have watched butterflies emerge and sit, trembling, while the sun irons their winds smooth. I have watched Tigers, like flames, mating in the long grass. I have been dive-bombed by an angry Raven, black and glossy as the Devil’s hoof. I have lain in water warm as milk, soft as silk, while around me played a host of Dolphins. I have met a thousand animals and seen a thousand wonderful things… but —
All this I did without you. This was my loss.
All this I want to do with you. This will be my gain.
All this I would gladly have forgone for the sake of one minute of your company, for your laugh, your voice, your eyes, hair, lips, body, and above all for your sweet, ever surprising mind which is an enchanting quarry in which it is my privilege to delve.

Translations, From the French

The Hands of the Father
Unspoken Sermons, First Series (1867)