Yogatattva Upaniṣad 54

54

padmāsanasthito yogī tathā gacchati bhūtale |
tato'dhikatarabhyāsādbhūmityāgaśca jāyate ||

The proficient in yoga should abandon the food detrimental to the practice of yoga. He should give up salt, mustard, things sour, hot, pungent, or bitter, vegetables, asafœtida, etc., worship of fire, women, walking, bathing at sunrise, emaciation of the body by fasts, etc. During the early stages of practice, food of milk and ghee is ordained; also food consisting of wheat, green pulse and red rice are said to favour the progress. Then he will be able to retain his breath as long as he likes. By thus retaining the breath as long as he likes, kevala kumbhaka (cessation of breath without inspiration and expiration) is attained. When kevala kumbhaka is attained by one, and thus expiration and inspiration are dispensed with, there is nothing unattainable in the three worlds to him. In the commencement (of his practice), sweat is given out; he should wipe it off. Even after that, owing to the retaining of the breath, the person practising it gets phlegm. Then by an increased practice of ḍhāraṇā, sweat arises. As a frog moves by leaps, so the yogin sitting in the Paḍma posture moves on the earth. With a (further) increased practice, he is able to rise from the ground. He, while seated in Paḍma posture, levitates. There arises to him the power to perform extraordinary feats. He does (or should) not disclose to others his feats of great powers (in the path). Any pain small or great, does not affect the yogin. Then excretions and sleep are diminished;