Just observe the momentary arising of mind in the relationship of the sense faculties and sense data; the arising of mind is conditional, and the mind of conditional terminology is the basis of delusion and understanding. This means the four truths have infinite characteristics; there is nothing else in the triple world but the making of one mind, and the mind is like a painter, making various forms. The mind constructs the six states of existence and discriminates and compares infinitely various differences, such as, for example, that such and such views and cravings are characteristic of light or heavy causes of suffering in the world or characteristic of light or heavy causes of suffering beyond the world, or that such and such birth and death is characteristic of light or heavy suffering of individual birth and death, or characteristic of light or heavy birth and death beyond the world. By overturning this mind, one produces understanding, like a painter washing off colors and applying whitewash.
That means contemplating the body as impure and mind as inconstant. These items of the path lead indirectly to the magic citadel.
Chih-i, Stopping and Seeing, p. 31-32