Bhagavad Gita · 3.39

आवृतं ज्ञानमेतेन ज्ञानिनो नित्यवैरिणा।कामरूपेण कौन्तेय दुष्पूरेणानलेन च॥

āvṛtaṁ jñānam etena jñānino nitya-vairiṇā kāma-rūpeṇa kaunteya duṣhpūreṇānalena cha

O son of Kunti, knowledge is covered by this eternal enemy of the wise, which is in the form of desire — an insatiable fire that can never be satisfied.

— Bhagavad Gita 3.39

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)