Like the bat, the Sufi is asleep to 'things of the day' - the familiar struggle for existence which the ordinary man finds all-important - and vigilant while others are asleep. In other words, he keeps awake the spiritual attention dormant in others. That 'mankind sleeps in a nightmare of unfulfillment' is a commonplace of Sufi literature
Idries Shah (1964). “The Sufis”, Anchor Books