Being āsana the first limb of Haṭha Yoga, it is described first. Āsana provides stability, health, and lightness of body.

This verse marks the beginning of the section on āsanas and indicates why they are fundamental.

The three benefits of āsana:

1. Sthairya — Stability. Not only physical, but the capacity to remain motionless during meditation. External stability leads to internal stability.

2. Ārogya — Health. The body free of illness can dedicate itself to more subtle practices. Health is a prerequisite, not an end in itself.

3. Aṅga-lāghava — Lightness of body. A light body is not an obstacle to practice; it becomes an instrument receptive to prāṇa.

Prathamāṅga — “first limb” — situates āsana as the foundation upon which the other practices of Haṭha Yoga are built.