हठयोग प्रदीपिका (योगी स्वात्माराम - ज्योत्स्ना टीका सहित सटीक)

HAṬHAYOGAPRADĪPIKĀ 37
78. The signs of [perfection in] Haṭha-yoga are:
Slimness of body, brightness in the face, manifestation
of the inner sound (nāda), very clear eyes, freedom
from disease, control over the seminal fluid, stimulation
of the [digestive] fire and complete purification of the
Nāḍī-s.