It is simply the Dharma gate of repose and bliss, the practice-realization of totally culminated enlightenment. It is the manifestation of ultimate reality. Traps and snares can never reach it. Once its heart is grasped, you are like the dragon when he gains the water, like the tiger when she enters the mountain. For you must know that just there (in zazen) the right Dharma is manifesting itself and that, from the first, dullness and distraction are struck aside.