Bhagavad Gita Chapter 4, Verse 42

तस्मादज्ञानसम्भूतं हृत्स्थं ज्ञानासिनात्मनः | छित्त्वैनं संशयं योगमातिष्ठोत्तिष्ठ भारत ||

tasmād ajñānasambhūtaṁ hṛtsthaṁ jñānāsinātmanaḥ chittvainaṁ saṁśayaṁ yogam ātiṣṭhottṣṭha bhārata

Therefore, cutting asunder with the sword of knowledge this doubt, born of ignorance, residing in your heart, take up yoga, O descendant of Bharata, and arise!

Krishna concludes Chapter 4 with a powerful call to action: 'chittvainaṁ saṁśayaṁ yogam ātiṣṭhottṣṭha bhārata' (cut this doubt with the sword of knowledge, take up yoga, and arise!). The metaphor of knowledge as a sword ('jñānāsinā') emphasizes that knowledge actively destroys doubt—it's not passive understanding, but active cutting away of ignorance. 'Hṛtsthaṁ' (residing in the heart) shows doubt is deeply rooted—not superficial, but at the core. 'Ajñānasambhūtam' (born of ignorance) shows doubt's source—ignorance creates uncertainty. The call to 'arise' ('uttiṣṭha') emphasizes action—don't just understand, but act. This verse concludes the chapter by combining knowledge and action—cut doubt with knowledge, take up practice (yoga), and engage in life. It's the perfect ending—knowledge that leads to action, understanding that leads to engagement.