From "Instructions to a Samurai" by Hakuin Ekaku
If you think dead sitting in silent awareness is enough, you'll waste your life and deviate greatly from the way of enlightenment. Not only will you deviate from the way of enlightenment, you'll neglect worldly truth too. Why? If the lords and grandees gave up government to sit deathlike in silent awareness, if the warriors ignored archery and horsemanship and forgot martial arts to sit deathlike in silent awareness, if the merchants closed up shop and broke their abacuses to sit deathlike in silent awareness, if carpenters discarded their plumb lines and tossed away their planes to sit deathlike in silent awareness, the nation would wither, the people would weary, robbers would rise up repeatedly, an the state would be in peril. Then the people would indignantly say that Zen is extremely inauspicious.
There are two kinds of selflessness. Suppose there is someone who is always timid and weak in body and mind, afraid of everyone, mortifying his feelings so that in dealing with myriad situations he does not become angry when hollered at, doesn't mind if he's beaten, is always absentminded, and doesn't learn from experience, but he thinks he has attained selflessness and considers that sufficient. This is being a broken rice bag, a fat-bellied pig in the mud, as if entirely ignorant and void of intelligence. It is not true selflessness.
~~~If you always have your mental energy filling your navel sphere, ocean of energy, elixir field, and the space between your waist and legs, and you do not let it recede for a moment even when you are busy working or meeting guests, then basic energy will fill the elixir field, and the lower abdomen will be slightly rounded like an unribbed ball.
If people can cultivate this state, they can sit all day without tiring, recite all day without wearying, write all day without fatigue, speak all day without getting worn out. Even if they do myriad good deeds day in and day out, they never show any sign of flagging. The mind becomes broader, the heart becomes bigger, energy is always vigorous. Even in the hottest summer one does not sweat, even without using a fan; even on the coldest winter night one does not need to wear socks or use a warmer. Even if one lives to be one hundred years old, one's teeth will become even firmer. If one does not slack off, one attains long life.
~~~There are three places in the body that are elixir fields. What I refer to as the elixir field is the lower elixir field. The ocean of energy and the elixir field are both below the navel, as if they were one reality with two names. The elixir field is two inches below the navel, the energy ocean an inch and a half. When pure energy always fills here, body and mind are always equanimous. Even if you live to be a hundred years old, your hair won't thin and your teeth won't loosen. Your vision will get clearer and your skin will gradually become lustrous.
~~~Spirit is like the ruler, vitality is like the ministers, and energy is like the people. Now then, caring for the people is the means of keeping the country intact. To be sparing of your energy is the means of keeping your body intact. When the people flee, The country perishes; when energy runs out, the body dies. For this reason, a sage ruler always focuses his mind below, while a mediocre ruler always indulges his heart on high. When the heart is indulged on high, the nobles rely on personal favor, the officials are arrogant with power; they never pay attention to hardship among the people, while importunate ministers greedily skim and cruel officers deprive by deception. There may be plenty of vegetables in the fields, yet people are collapsing from starvation in the countryside. The intelligent and the good go into hiding, ministers and commoners are angry and resentful, the masses of people are ultimately reduced to abject misery and so the pulse of the nation dies out forever.
When the mind is focused below, never forgetting the toil of the people, the populace is well-nourished and the state is strong; no ministers or commoners violate the law, while no enemy states invade the domain. So it is with the human body. The perfect people always have mental energy filling below, so the emotions do not act within, while the material world cannot invade from without. With the camp guard fully supplied, the mental spirit is strong. Ultimately, the body doesn't know the sting of acupuncture or moxabustion, just as the people of a powerful nation don't hear cries of alarm.
ns