Posture is steady and comfortable.

This is the most cited sutra on āsana, and probably the most misunderstood.

Sthira is stability, firmness, without agitation or trembling.

Sukha is comfort, ease, literally “good space.” The posture should not cause tension or pain.

Patañjali doesn’t prescribe specific postures or acrobatics. The āsana of the Yoga Sutras is the meditation posture: the body must be able to remain still for long periods without distracting the mind.

This sutra establishes the criterion: any posture that is stable and comfortable is valid. The emphasis is not on external form but on the internal quality of the experience.

The body, when well positioned, disappears from consciousness.