Kṛṣṇa describes the nature of this internal enemy. It is the ‘nitya-vairiṇā’, the eternal enemy of the wise soul. It takes the form of lust, which is like an insatiable fire. Fire never says “I have had enough wood”; the more you add, the more it consumes. Many people think that by satisfying a desire, it will go away. Kṛṣṇa says the opposite is true. Satisfying lust only makes it stronger and more demanding. It is a trap designed to keep the soul enslaved to the senses forever. The wise person recognizes this and treats lust with caution. This fire of desire covers our ‘jñānam’, or knowledge, making us act in ways that are against our own long-term interests. Kṛṣṇa is telling Arjuna that he cannot negotiate with his cravings. He must recognize them as a permanent threat to his spiritual clarity and treat them as an enemy to be conquered, not a guest to be entertained.