TAO TE CHING LII

That which was the beginning of all things under heaven We may speak of as the “mother” of all things. He who apprehends the mother Thereby knows the sons. And he who has known the sons, Will hold all the tighter to the mother, And to the end of his days suffer no harm; “Block the passages, shut the doors, And till the end your strength shall not fail. Open up the passages, increase your doings, And till your last day no help shall come to you.” As good sight means seeing what is very small So strength means holding on to what is weak. He who having used the outer-light can return to the innerlight Is thereby preserved from all harm. This is called resorting to the always-so.