The fire Vaiśvānara who is within the person, and who is the conscious Self — to him, they say, the brahmacharya student goes with firewood in hand, versed in the Vedas.

The identification of the interior fire with the conscious Self.

Agniḥ vaiśvānaraḥ — the universal fire. The same cosmic fire present in every being.

Antaḥ puruṣe — within the person. Not remote but immediate, at the center of being.

Caitanyātmā — the conscious Self. The Ātman as principle of consciousness, of luminosity.

Samit-pāṇiḥ — with firewood in hand. The symbol of requesting teaching, of disposition to the sacrifice of knowledge.

Brahmacārī — the brahmacharya student. One who practices continence and study, preparing for realization.

Śrotriyaḥ — versed in the Vedas. Textual knowledge as foundation, not substitute, for realization.

The interior fire is the Ātman itself. Yoga is to feed that fire with practice, with attention, with the sacrifice of ego.