Everything that is alive draws in life energy and expresses it in a process corresponding to respiration.
Our life begins at our birth with an inhalation and our life will end with our last exhalation. From cradle to the grave our breathing function does not let us down except in times of respiratory malfunction or disease. Throughout the whole period of our life-span the breath will continue without a pause, in its interminable rhythm keeping us supplied with oxygen, giving us life energy whether we are aware of the process.
The majority of these breaths we take unconsciously, with many being taken in the hours of sleep. But we expect that when we go to sleep, the breath will continue, and that when we awaken, the process will have been maintained through our sleep and naturally be resumed.
It is a potent reminder of the absolute faith that we place in nature every time we go to sleep.