Śivasaṃhitā 3.71

Paricayāvasthā (the state of intimate familiarity) arises abhyāsataḥ — from practice itself, as natural fruit. The Śivasaṃhitā uses the moon and sun metaphor here: when vāyu abandons the lunar (iḍā) and solar (piṅgalā) channels and stabilizes in the stillness of suṣumnā, the practitioner has transcended fundamental respiratory duality. The breath no longer alternates: it has found the channel that knows no opposites.

Candrasūrya tyaktvā — having abandoned the moon and sun — is the most poetic description of prāṇa settling into suṣumnā. Niścala (motionless, still, without oscillation) describes not paralysis but fullness: movement that has found its natural equilibrium point. Like a pendulum reaching dead center, not because it has lost energy but because it has perfectly accumulated it.

The yogin who «drinks the ambrosial air» (amṛtanilaṃ pibati) daily destroys specific diseases: śrama (accumulated fatigue), dāha (burning sensation, internal fever), jarā (degeneration, senility) and abhighāta (injuries, traumatisms). Four consequences of aging and deterioration that prāṇāyāma reverses — according to the text — in a physiologically real and verifiable way.