Rumi - Silence is the guide

 "The story admits of being told up to this point,
  But what follows is hidden, and inexpressible in words.
  If you should speak and try a hundred ways to express it,
  'Tis useless; the mystery becomes no clearer,
  You can ride on saddle and horse to the sea-coast,
  But then you must use a horse of wood (i.e. a boat).
  A horse of wood is useless on dry land,
  It is the special vehicle of voyagers by sea.
  Silence is this horse of wood,
  Silence is the guide and support of men at sea."

  The Masnavi of Jalaluddin Rumi