Samādhi Is the Product of the Integration of Concentration and Wisdom.

Whether it is the sun contemplation of the Contemplation Sutra of Infinite Life, the white-bone contemplation, or any other contemplative practice (vipaśyanā-caryā), when it finally reaches accomplishment, without the mind consciousness directing attention, that image will appear whether the eyes are open or closed; and of course, if the mind consciousness does direct attention, the image will become even clearer.

So-called accomplishment means it appears naturally and spontaneously—that is called meditative concentration/meditative absorption (samādhi). If it cannot appear naturally and spontaneously, and must appear only when the mind consciousness directs attention, then it does not count as accomplishment and is not samādhi. So-called samādhi is a very deep state of meditative concentration, but this does not exclude it simultaneously containing a state of wisdom; the organic combination of wisdom and meditative concentration is called samādhi—lacking either one, it is not samādhi. Within such samādhi there is already relatively deep meditative concentration, and the manas must certainly have been trained to maturity. Once the manas has been trained to maturity, it can operate at every moment, and thus this image is manifested 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 habituated—it is merely that the mind consciousness has become relatively proficient. When the mind consciousness is proficient and directs attention, it draws the manas along; only then can the manas direct attention, and afterward the state manifests. Such a state is therefore not proficient—it is intermittent, and this power of concentration is insufficient, so it cannot be called samādhi.