When purification of the nāḍīs occurs, there are external signs: thinness of the body and luminosity appear with certainty.

This verse describes the external signs (cihnāni bāhyataḥ) indicating that nāḍīśuddhi (purification of the energy channels) has occurred. These signs are verifiable and objective, not merely subjective.

The first sign is kṛśatā — thinness or slenderness of the body. Regular prāṇāyāma practice burns excess fat and impure tissues. Metabolism is optimized and the body reaches its natural ideal weight. This thinness is not weakness but refinement.

The second sign is kānti — luminosity, radiance, or glow. The skin acquires a healthy luster, the eyes shine with clarity, and the entire being radiates vitality. This luminosity is the external reflection of internal purity. Traditional masters can evaluate a student’s progress by observing these physical signs.