Śivasaṃhitā 3.91

The technique of pressing teeth against teeth (dantairdantānsamāpīḍya) during slow inhalation creates resistance regulating the speed and quality of ingested air. The clenched jaw activates the pterygoid and masseter muscles, which have neurological connections with the autonomic nervous system through the trigeminal nerve. This subtle activation modifies the central nervous system’s state: a somatosensory technique of autonomic regulation predating any pharmacology.

«Knowing the action of prāṇa and apāna» (prāṇāpānagatiṃ jñātvā) is the condition of the yogin attaining emancipation in padmasana. Not conceptual knowledge — that the airs ascend and descend — but experiential knowledge: feeling in the body how prāṇa ascends from the nābhi and apāna descends toward the perineum, how in retention both meet at the nābhicakra and produce the bindu that ignites the fire of realization.

The final double affirmation — satyam, satyam I tell you — echoes verse 80’s formula and marks the closure of the padmasana teaching cycle. Emancipation (mukti) through padmasana + prāṇāyāma + prāṇa knowledge is not a future hope but a direct consequence of correct practice. The double emphasis is the master’s guarantee: one who has lived this can affirm it with this certainty.