坐禪三昧經 1.15

1.15

If the mind dwells for a long time, it accords with the dhyāna dharma. If one attains dhyāna concentration, there are three marks: the body is harmoniously pleased, supple, and nimble; the white bones radiate light like white conch shell; and the mind attains tranquil stability. This is contemplation of the pure. At this time one then attains the mind of the form realm; this is called attaining the mind of the form realm for a beginner learning the dhyāna dharma. When the mind accords with the dhyāna dharma, that is the dharma of the form realm. When the mind attains this dharma, while the body remains in the desire realm, the four great elements become immensely supple, joyful, smooth, pure, radiant, and harmonious—this is called joy. Second, in the white-bone mark of the bone contemplation just mentioned, light shines everywhere in a pure white color. Third, the mind dwelling in one place is called pure contemplation; because one removes the flesh and contemplates the bone, it is called pure contemplation. As for the three marks above, one knows them oneself, while others cannot see them. The three grades above are: the beginning practitioner, who has not previously aroused the intention; the one who has already practiced, having cultivated it over three or four lifetimes; and the one who has long practiced, having trained over hundreds of lifetimes.