Śvetāśvatara Upaniṣad · 2..5

वयं त्वग्नेः प्रथमं नमो अद्य तद् वयमुपब्रुवीमहे देवेभ्यः पितृभ्यश्च

vayaṃ tvagneḥ prathamaṃ namo adya tad vayamupabruvīmahe devebhyaḥ pitṛbhyaśca

To you, Agni, we offer our first reverence today. This we proclaim to the gods and to the ancestors.

Agni, the fire, is the mediator between worlds: he consumes offerings and transports them, illuminates and transforms. Namas (reverence) offered first to Him recognizes that every subsequent sacrifice depends on His presence. In our yoga practice, Agni is the inner fire of digestion, of *tāpa (spiritual heat), of transformation. Proclaiming this to the devas (gods) and pitṛs (ancestors) establishes continuity: we are not alone in our effort, but part of a current of wisdom connecting earth and heaven, past and present.