坐禪三昧經 2.14

2.14

Next, one trains in the five supernormal knowledges, [whereby] the body can fly through the air and transform at will. The practitioner focuses their mind on samādhi born of desire, samādhi born of vīrya, samādhi born of single-mindedness, and samādhi born of wisdom. With single-mindedness, one contemplates the body, constantly forming the perception of lightness, wishing to accomplish flight. Whether [this perception] is too great or too small (excessive samādhi born of desire being "too great," and deficient samādhi born of desire being "too small")—both of these are faults. Exerting oneself with vīrya and ever able to be single-minded, one meditates on the contemplation of lightness: just like a person who can float, who does not sink because their mental strength is powerful; or like a monkey that falls from a height and suffers no pain or harm to its body because its mental strength is powerful. This too is like that: one causes the power of desire, the power of vīrya, the power of single-mindedness, and the power of wisdom to become vast and great, and the body [to become] ever lighter and smaller, whereupon one is able to transport the body.