Śivasaṃhitā 2.33

The solar sphere (sūryamaṇḍala) in which the abdominal fire is said to reside is not merely an anatomical landmark but a cosmological one. By locating the digestive fire at the center of the sun’s disc within the body, the text maps cosmic and somatic orders onto each other — the same solar principle that ripens grain in the field transforms food within the human organism.

The twelve kalās — phases or digits — attributed to the sun are a recurring motif in Vedic and Tantric literature, where they represent the sun’s complete cycle of powers. Kalā itself derives from the root kal (to count, to impel), and its application here suggests that the internal fire operates in measured, rhythmic phases rather than as a constant, undifferentiated heat. This cyclical quality aligns with Āyurvedic teachings on the variable strength of agni throughout the day.

The identification of this fire with Vaiśvānara — a name appearing in the Chāndogya Upaniṣad (5.18) for the universal Self dwelling as digestive fire in all beings — gives the verse deep Upaniṣadic roots. The Śivasaṃhitā thus situates its physiological teaching within a long theological lineage, presenting digestion not as a merely biological event but as a sacred, theophanic process occurring continuously within every living body.