In this powerful metaphor, Krishna illuminates the transformative nature of self-knowledge (Jnana). The 'blazing fire' is not merely an intellectual understanding, but the direct, experiential realization of one's true nature as the Atman, which is eternally untouched by the constructs of cause and effect. Just as fire fundamentally alters the nature of wood until it can no longer be used as fuel, the fire of transcendental knowledge consumes the 'karmic residue'—the binding impressions and fruitive reactions—that anchor the soul to the cycle of samsara. By shifting identity from the ego-doer to the witness-consciousness, the seeker ceases to generate new karmic seeds, while the mountain of past actions is reduced to ash, rendering it powerless to bind the soul to future rebirths.

True knowledge does not just modify behavior; it annihilates the root of egoic entanglement, burning away the illusory bond between the actor and the fruits of action.