That they consider yoga: the firm withdrawal of the senses. Then one becomes vigilant, for yoga is origin and dissolution.

Here yoga is defined in its essence: sthira indriyadhāraṇā (the firm withdrawal of the senses). It is not physical posture or breathing technique; it is the capacity to keep the senses still, not being dragged by their objects. The apramatta (vigilant, not negligent) is one who possesses this constant wakefulness.

Yoga is prabhavāpyayau (origin and dissolution). It is the place from which everything arises and to which everything returns. To practice yoga means to align with this fundamental principle of existence: to be the witness of the manifestation and reabsorption of all phenomena.

This definition protects us from reducing yoga to physical exercise. The yogī is one whose senses are under firm control, whose mind is quiet, and who remains awake to the reality beyond sleep and waking. This vigilance is the heart of all authentic practice.