Sleep is cousin-german unto death: Sleep and death differ, no more, than a carcass And a skeleton.

-Traherne,Thomas
'A Serious and a Curious Night-Meditation' (published1903).

   To be, or not to be; that is the bare bodkin That makes calamity of so long life; For who would fardels bear, till Birnam Wood do come to Dunsinane, But that the fear of something after death Murders the innocent sleep, Great nature's second course, And makes us rather sling the arrows of outrageous fortune Than fly to others that we know not of. There's the respect must give us pause: Wake Duncan with thy knocking! I would thou couldst; For who would bear the whips and scorns of time,

-Twain, Mark pseudonym of  Samuel Langhorne Clemens

If you are with the quality, or at a funeral, or trying to go to sleep when you ain't sleepy†why you itch all over in upward of a thousand places.

-Twain, Mark pseudonym of  Samuel Langhorne Clemens
  TheAdventures of Huckleberry Finn, ch.2.

I haven't been to sleep for over a year. That's why I go to bed early.One needs more rest if one doesn't sleep.

-Waugh, Evelyn Arthur StJohn
  Decline and Fall, pt.2, ch.3.

They that sleep with dogs shall rise with fleas.

-Webster,John
  TheWhite Devil, act 5, sc.1.

Beyond the gap where the river plunges into the narrow gorge, unseen öand the imagination soars, as a voice beckons, a thundrous voice, endless öas sleep: the voice that has ineluctably called themö that unmoving roar!

-Williams,William Carlos
  Paterson, bk.2,'Sunday in the Park',1.

   The greatest asset that a head of state can have is the ability to get a good night's sleep.

-Wilson of Rievaulx, (James) Harold Wilson, Baron
  BBC Radio 4 broadcast,16 Apr.

   The main essentials of a successful Prime Minister are sleep and a sense of history.

-Wilson of Rievaulx, (James) Harold Wilson, Baron
  The Governance of Britain.

Our birth is but a sleep and a forgetting: The soul that rises with us, our life's star, Hath had elsewhere its setting, And cometh from afar: Not in entire forgetfulness And not in utter nakedness, But trailing clouds of glory do we come From God, who is our home: Heaven lies about us in our infancy! Shades of the prison-house begin to close Upon the growing boy, But he beholds the light, and whence it flows, He sees it in his joy; The youth, who daily farther from the east Must travel, still is nature's priest, And by the vision splendid Is on his wayattended; At length the man perceives it die away, And fade into the light of common day.

-Wordsworth,William
c.1802^1803  'Ode. Intimations of Immortality from Recollections of Early Childhood', stanza 5 (published1807).

When you are old and greyand full of sleep, And nodding by the fire, take down this book, And slowly read, and dream of the soft look Your eyes had once, and of their shadows deep; How many loved your moments of glad grace, And loved your beauty with love false or true, But one man loved the pilgrim soul in you, And loved the sorrows of your changing face; And bending down beside the glowing bars, Murmur, a little sadly how Love fled And paced among the mountains overhead And hid his face amid a crowd of stars.

-Yeats,W(illiam) B(utler)
  'WhenYou Are Old', complete poem. Collected in The Rose (1893).