Therefore with the sword of the knowledge (of the Self) cut asunder the doubt of the self born of ignorance, residing in thy heart, and take refuge in Yoga. Arise, O Arjuna.
In simple words
Krishna closes the chapter with a call to action: "So Arjuna, take the sword of knowledge and cut through this doubt sitting in your heart — this doubt born from not knowing who you truly are. Stand up. Take refuge in yoga. Rise."
Word-by-word meanings
तस्मात्thereforeअज्ञानसंभूतम्born out of ignoranceहृत्स्थम्residing in the heartज्ञानासिनाby the sword of knowledgeआत्मनःof the Selfछित्त्वाhaving cutएनम्thisसंशयम्doubtयोगम्Yogaआत्तिष्ठtake refugeउत्तिष्ठariseभारतO Bharata
Contemporary scholarly and practical interpretations for modern seekers.
Swami Sivananda
4.42 तस्मात् therefore? अज्ञानसंभूतम् born out of ignorance? हृत्स्थम् residing in the heart? ज्ञानासिना by the sword of knowledge? आत्मनः of the Self? छित्त्वा having cut? एनम् this? संशयम् doubt? योगम् Yoga? आत्तिष्ठ take refuge? उत्तिष्ठ arise? भारत O Bharata.Commentary Doubt causes a great deal of mental torment. It is most sinful. It is born of ignorance. Kill it ruthlessly with the knowledge of the Self. Now stand up and fight? O Arjuna.(This chapter is known by the names Jnana Yoga? Abhyasa Yoga and jnanakarmasannyasa Yoga also.)Thus in the Upanishads of the glorious Bhagavad Gita? the science of the Eternal? the scripture of Yoga? the dialogue between Sri Krishna and Arjuna? ends the fourth discourse entitledThe Yoga of the Division of Wisdom. ,
Swami Chinmayananda
This interpretation draws on a specific tradition and may not represent the view of any single school. For authoritative guidance within a specific tradition, seek a qualified teacher.
In this final verse, the assent given by Sri Krishna, though brief, is suffused with affection. This verse resonates with his tender regard for Arjuna. The teachings of the sages, imparted in the serene and solitary mountain valleys of the Himalayas, are here explained by Sri Krishna to his warrior-companion Arjuna in the language of battle itself. He encourages Arjuna to sever the doubts concerning the Self that arise from ignorance dwelling in the heart, wielding the sword of knowledge.
Here, doubt is said to reside in the heart, which may seem strange to the educated person of today, for doubt arises from the intellect, not from the heart. According to Vedantic understanding, the intellect's dwelling place is the heart. Yet the physical heart as a bodily organ is not what is meant here. In philosophy, the word "heart" is employed in a psychological and literary sense. Love, compassion, and the noblest and most ideal sentiments of humanity spring from the heart. The intellect that works from a heart filled with such love is what, from the philosophical perspective, may truly be called human intellect. Therefore, when doubt is said to reside in the heart, it refers to the corrupted intellect of certain seekers, which prevents them from realizing the Self. The ultimate cessation of all manner of doubts becomes possible only when the seeker directly experiences the Self. This is possible through the practice of yoga. Yet yoga does not mean some mysterious discipline that only a rare teacher will reveal in secret, nor is it a practice that must be undertaken sitting in the desolate caves of the Himalayas. All the false notions that generate fear regarding yoga are dispelled forever in the Gita, and that word is rendered familiar and practical. Yoga is useful in all fields of life. The twelve types of sacrifice described by Lord Sri Krishna in this chapter are precisely what is meant by the word yoga. This chapter concludes with a call to Arjuna to rise—Arise, O Bharata. Though in the context of the Gita's teaching, the word Bharata addresses Arjuna himself, yet through Arjuna, all seekers are summoned here. By practicing sacrifice and discipline, we must increasingly purify our inner being, so that through deep meditation we may attain the supreme goal of evolution—eternal peace.
Thus concludes the Fourth Chapter, named the Yoga of Knowledge and the Renunciation of Action, in the Upanishads of the Blessed Bhagavad Gita, the scripture of Brahma-knowledge, in the dialogue between Sri Krishna and Arjuna.