Don Quixote followed nature, and being satisfied with his first sleep, did not solicit more. As for Sancho, he never wanted a second, for the first lasted him from night to morning, indicating a sound body and a mind free from care; but his master, being unable to sleep himself awakened him, saying, "I am amazed, Sancho, at the torpor of thy soul; it seems as if thou wert made of marble or brass, insensible of emotion or sentiment!
Miguel de Cervantes Saavedra (1866). “Adventures of Don Quixote de la Mancha”, p.681