Śivasaṃhitā 3.84

Rasanāṃ tālumūle sthāpayitvā — having placed the tongue at the palate root — is the minimal description of khecarīmudrā: not the advanced version requiring frenulum elongation, but the basic gesture of pressing the tongue tip against the soft palate just behind the upper dental cavity. This point activates the vagus nerve and creates the internal circuit allowing direct absorption of prāṇavāyu.

Prāṇavāyu pibati (drinks the prāṇavāyu) is an image interpretable either literally — the yogin inhales prāṇa through this subtle opening — or symbolically: absorption of primordial prāṇa (mahāprāṇa) circulating in the internal space (cidākāśa) and normally inaccessible to ordinary senses. The vicakṣaṇa (the skillful, the one of sharp vision) is one who has refined their perception sufficiently to distinguish between ordinary air and subtle prāṇa.

«Complete dissolution of all yogas» as result of this simple and powerful practice underscores a central paradox of the haṭhayogic tradition: the most advanced techniques are not the most complicated but the most direct. Khecarīmudrā, practiced with mastery, dissolves the need for any other yoga — prāṇāyāma, āsana, dhāraṇā — because it acts at the origin point of all techniques: the point where prāṇa and consciousness meet.