Śivasaṃhitā 3.26

The practice of prāṇāyāma demands patience above all. The instruction to exhale slowly — śanaiḥ śanaiḥ, the doubled repetition emphasizing the urgency of gradualness — subverts our tendency to force the breath. Twenty repetitions are not an arbitrary number: they create the neurophysiological groove that transforms conscious exercise into lasting organic habit.

Iḍā nāḍī (the lunar current, the left channel) carries the breath outward in this recaka (exhalation) exercise. The term yogavidhāna — ordinance or legislation of yoga — reveals that the Śivasaṃhitā conceives practice as a precise normative code, not a vague recommendation. Viṃśati (twenty) appears here as an exact technical prescription, not an approximate figure.

In the Śaiva tantric tradition, iḍā is associated with the moon, coolness, and the receptive principle. Exhaling through the left nostril activates the candra channel before retention, preparing the nervous system for the necessary stillness. Medieval haṭhayoga masters inherited this protocol and codified it in texts such as the Haṭhapradīpikā, where the iḍā-recaka sequence holds a central place.