Śivasaṃhitā 3.90

Aharniśam (day and night, literally «day and darkness») describes a practice that has transcended the formal session to become a continuous state. The advanced yogin does not «practice» kākacañcvā during defined periods: their ordinary inhalation mode has itself become the technique. The crow’s beak form — lips slightly pursed — is their way of breathing both during meditation and in daily life.

The destruction of «all diseases» (rogāṇāṃ saṅkṣayo) as consequence of daily prāṇānilaṃ connects with āyurvedic vision: all diseases are prāṇa imbalances. The yogin maintaining prāṇa in constant equilibrium — its harmonious flow (samānatā) through all nāḍīs — has eliminated the cause of all disease. Perfect health is not the absence of pathogens; it is the presence of a prāṇa so dynamic and balanced that no imbalance can establish itself.

The harmonization of prāṇavāyus through padmasana evidences once more the Śivasaṃhitā’s integrative vision: correct posture and correct prāṇāyāma produce a physiological state where the five vāyus (prāṇa, apāna, vyāna, udāna, samāna) circulate in their correct channels without interfering with each other. The result is perfect homeostasis: the body as a perfectly tuned instrument.