Śivasaṃhitā 4.72

Uḍḍīyānabandha receives its formal heading followed by an anatomically specific description of the technique: the posterior traction (paścimatāna) must be performed both in the supra-umbilical and infra-umbilical regions. This bidirectionality distinguishes the Uḍḍīyāna of the Śivasaṃhitā from simpler descriptions that only mention the upward movement of the diaphragm.

Paścima — ‘western, rear, posterior’ — in this anatomical context indicates the posterior direction of the body (toward the spine), not the cardinal point. The tāna (extension, traction) describes the movement of the abdomen toward the vertebral column during retention after complete exhalation: the internal vacuum created by exhalation and retention generates a negative pressure that ‘pulls’ abdominal contents backward and upward.

Sarvaguhyatamaṃ guhyam — ‘the most secret among all secrets’ — reappears here applied to Uḍḍīyāna, as it was previously applied to Vajrolī (verse 53). This repetition of the secrecy superlative does not indicate redundancy but a value scale where the most physically transformative teachings are the most jealously protected. Uḍḍīyānabandha, through its direct effect on the maṇipūracakra and the digestive fire, has the potential to radically accelerate the body’s energetic processes, with unpredictable effects without appropriate guidance.