Śivasaṃhitā 2.27

Suṣumṇā occupies the central axis of the subtle body and is unquestionably the most sacred channel in yogic anatomy. Positioned between the two polar currents, it is not merely a midpoint but a qualitatively distinct dimension: the space where solar-lunar duality dissolves and prāṇa can ascend toward liberation. The six stages mentioned here correspond to the six principal cakras along its path.

The name suṣumṇā is etymologically debated, but is generally interpreted as ‘the most gracious’ or ‘she who grants supreme bliss’, derived from the prefix su- (good, excellent) and a root related to divine favor. Within Suṣumṇā, tradition describes progressively subtler inner channels: vajriṇī, citrā, and brahmanāḍī, culminating in the brahmarandhra at the crown of the skull.

Awakening Suṣumṇā is the central technical aim of Haṭha Yoga practice. As long as prāṇa flows only through Iḍā and Piṅgalā, the mind remains caught in duality. Only when both currents are perfectly balanced and prāṇa enters Suṣumṇā does the state of khecarī arise, the mind grow still, and samādhi become accessible. This verse locates that threshold with anatomical precision.