Kṛṣṇa uses a striking fire analogy. Just as a blazing fire turns a heavy pile of firewood into a handful of weightless ash, the fire of knowledge burns to ashes all the reactions of past material activities. It completely neutralizes the karma of the soul. Karma is like a mountain of wood we have collected over millions of lifetimes. We expect to spend millions more lifetimes ‘burning’ it through suffering and enjoyment. But Kṛṣṇa says there is a shortcut: the ‘jñānāgniḥ’, or the fire of knowledge. One spark of real realization—that I am not this body, I am a servant of Kṛṣṇa—incinerates the entire pile at once. This is why spiritual knowledge is the most valuable asset. It frees us from the debt of our past mistakes. Arjuna is worried about the future reactions to his actions on the battlefield, but Kṛṣṇa assures him that acting in this knowledge will prevent any new karma from forming and will wipe out the old. The fire of truth is the ultimate purifier.