Nous veillons dormants, et veillants dormons. We wake sleeping, and sleep waking.

-Montaigne, Michel Eyquem de
  Essais, bk.2, ch.12 (translated by Charles Cotton).

For eight years I was sleeping with the President, and if that doesn't give you special access, I don't know what does!

-Reagan, Nancy
  MyTurn (withWilliam Novack).

Jock, when ye hae naething else to do, ye may be aye sticking in a tree; it will be growing, Jock, when ye're sleeping.

-Scott, Sir Walter
  The Laird of Dumbiedikes to his son.The Heart of Midlothian, ch.8.

I have never taken any exercise, except sleeping and resting, and I never intend to take any. Exercise is loathsome.

-Twain, Mark pseudonym of  Samuel Langhorne Clemens
Quoted in ColinJarmanThe Guinness Dictionary of Sports Quotations (1990).