Meditative concentration (samādhi) is the product of the union of meditation and wisdom.

Whether it is the sun contemplation of the Contemplation of the Buddha of Infinite Life Sūtra, the white-bone contemplation, or any of the various other contemplative practices (vipaśyanā-caryā), when they finally reach accomplishment, without the mind consciousness deliberately engaging, that image will appear whether the eyes are open or closed; of course, if the mind consciousness does deliberately engage, the image will become even more distinct.

What is called accomplishment is that it arises naturally and spontaneously—that is called meditative concentration/meditative absorption (samādhi). If it cannot arise naturally and spontaneously, and can only appear when the mind consciousness deliberately engages, then it does not count as accomplishment and is not samādhi. What is called samādhi is a very deep state of meditative concentration, but this does not exclude the possibility that a state of wisdom is present at the same time; the organic integration of wisdom and meditative concentration is called samādhi, and lacking either one, it is not samādhi. Within such samādhi there is already fairly deep meditative concentration, and the manas must certainly have been trained to maturity as well. Once the manas has been trained to maturity, it can operate at every moment, and then this image will manifest in the mind at every moment.

If your power of meditative concentration has not been cultivated to accomplishment, then samādhi has not been cultivated to accomplishment; the manas has not been successfully permeated—it is merely that the mind consciousness has become more practiced. When the mind consciousness is practiced and deliberately engages, it draws the manas along; only then can the manas deliberately engage, and afterward the state manifests. Such a state is therefore not practiced and fluent, but intermittent; this power of concentration is insufficient, and so it cannot be called samādhi.