Śivasaṃhitā 4.50

The period of six months (ṣaṇmāsa) to obtain mastery over death is one of the specific temporal markers of the Śivasaṃhitā, distinguishing this tradition from vaguer approaches. Six months correspond to a solar semester, the transition between two ayanas (halves of the year), marking a complete transformation cycle. Practice thus temporalized suggests a sādhana pedagogy based on natural cycles.

Siddhimīpsubhiḥ — ‘by those who desire to achieve success’ — combines siddhi (perfection, achievement, obtained power) with the desiderative īpsubhiḥ (from āp-, to obtain, in desiderative form: ‘those who wish to obtain’). The dual motivation — secrecy to protect the practice, longing as engine — creates the proper dynamic tension for the serious practitioner. Agnivardhanam (increase of fire) and dehadravyavṛddhi (increase of bodily fluids) are concrete physiological effects of Uḍḍīyāna.

The apparent paradox — fire and fluids increase simultaneously — is resolved in subtle physiology: the agni potentiated by practice does not burn but refines, acting like the flame under an alembic that transforms crude liquid into distilled essence. The fluids that increase are the refined rasas: ojas (immunity), tejas (radiance), prāṇa (vitality) — not ordinary humors.