Compressing his breaths in here and curbing his movements, a man should exhale through one nostril when his breath is exhausted. A wise man should keep his mind vigilantly under control, just as he would that wagon yoked to unruly horses.

Level and clean; free of gravel, fire, and sand; near noiseless running waters and the like; pleasing to the mind but not offensive to the eye; provided with a cave or a nook sheltered from the wind—in such a spot should one engage in yogic practice.

Mist, smoke, sun, wind, fire, fireflies, lightning, crystal, moon—these are the apparitions that, within yogic practice, precede and pave the way to the full manifestation in brahman.[1]

When earth, water, fire, air, and ether have arisen together, and the body made up of these five becomes equipped with the attribute of yoga, that man, obtaining a body tempered by the fire of yoga, will no longer experience sickness, old age, or suffering.

Lightness, health, the absence of greed, a bright complexion, a pleasant voice, a sweet smell, and very little faeces and urine—that, they say, is the first working of yogic practice.

From the Svetasvatara Upanishad, Upanishads, translated by Patrick Olivelle, Oxford: Oxford University Press, 1996, p. 256.

Footnote

1. Brahman has a variety of meanings, and it is impossible to use a single English term to designate all these meanings. It may mean “a formulation of truth,” the Veda, or the ultimate and basic essence of the cosmos—that is, the ultimate real. (Introduction, op. cit., p. lvi)