Śivasaṃhitā 5.73

The six-month timeline for vāyu to enter suṣumnā—the central event of haṭhayoga—is remarkably specific. The figure is not arbitrary: it corresponds to the classical physiological understanding that the body renews itself completely in six-month cycles, and that this renewal time is sufficient for regular prāṇāyāma to have reprogrammed habitual prāṇic flow patterns. The specificity of the timeline adds pedagogical credibility: the teacher who promises a concrete timeframe demonstrates first-hand knowledge.

Conquering the mind (manoviजaya), retaining the breath (prāṇa nirodha), and retaining semen (śukra dhāraṇa) are the three achievements the text presents as progress indicators at this level. They are not independent but expressions of the same process: when prāṇa enters suṣumnā, the mind quiets (manaḥśānti), breathing deepens and slows, and sexual energy sublimates into ojas. All three are facets of the same movement of prāṇa toward the central channel.

Success in “this world and the other” (ihaloka-paraloka) represents yoga’s dual promise: benefits in the present life (health, clarity, effectiveness) and liberation in the post-mortem transition. The tradition saw no opposition between these two objectives: the yogin who has purified his nāḍī and directed his prāṇa toward suṣumnā naturally obtains both. The quality of present life and the quality of death are, in the yogic perspective, aspects of the same refinement process.