"Calmness and insight develop through stilling thoughts: the mind of the buddhas manifests therein." This saying seems to refer to cessation and observation, or stopping and seeing.
The ocean of nature to which all things alike return is essentially united, quiet, always clear and calm. When it is stirred by the influences of conditions, then billows of consciousness and waves of emotion well up in ten thousand ways. If not for stopping, there is no way to clarify its clarity and calm its calmness.
The cosmos of reality completely manifesting unity is always evident and always clear when views are gone and things disappear. As soon as it is obscured by the dust of behavioral and intellectual obstructions, then the fog of confusion and clouds of delusion coalesce into myriad forms. If not for seeing, there is no way to bring to light its evident clarity.
When all agitations have ceased and not a single wave arises, myriad phenomena are clear, without confusion, without obstruction. Thus seeing is not separate from stopping. Once the layers of obscurity have been cleared and no clouding occurs, the ten directions are empty, without stirring, without agitation. Thus stopping is not outside of seeing.
Stopping is like concentration, seeing is like insight. Insofar as we see by stopping, concentration is the catalyst of insight; insofar as we stop by seeing, insight is the basis of concentration. When the catalyst of insight does not run dry, stopping is sufficient to assist the function of seeing; when the basis of concentration is not lacking, seeing is adequate to fulfill the achievement of stopping.
Stopping without seeing may deteriorate into stagnation; seeing without stopping may degenerate into inquisitiveness. Stopping is of course stopping motion, but it is also the root of motion. When stopping without seeing, one either falls into empty quiescence, or distraction arises. Seeing is of course illuminating the obscure, but it is also the root of obscurity. So when seeing without stopping, either one drifts into thought and reflection, or immersion in illusion occurs. Therefore stopping and seeing need each other; neither one can be neglected.
So this stopping is not intrinsic stopping. It depends on motion and stillness to manifest its achievement. And this seeing is not independent seeing; it depends on obscurity and clarity to reveal its function. Since they are not beyond achievement and function, how can they be called true stopping and true seeing?
If stopping and achievement are not set up, and seeing and function are both forgotten, after that both motion and stillness are stopping with true seeing, and both darkness and light are seeing with true stopping.
When stopping with true seeing merges motion and stillness, then the hundreds of thousands of buddhas enter into right concentration in the midst of billows of feeling and waves of consciousness, which do not harm that which is essentially unified and silent. When seeing with true stopping merges darkness and light, then the eighty thousand methods of practice illumine right knowledge in the midst of the fog of confusion and clouds of illusion, which do not inhibit that which causes views to vanish and things to disappear.
When you get to this, then thoughts become still without being stilled, calmness and insight arise without being produced, the mind of the buddhas appears without being revealed. To try to liken it to the body of cosmic space or the light of a thousand suns would be to be further away than the sky is from the earth.