Therefore, with the sword of knowledge, cut away this doubt about the self, born of ignorance and lodged in your heart. Take your stand in yoga and rise, O descendant of Bharata.
Explanation
Krishna closes the fourth chapter by speaking to Arjuna, who is paralysed by doubt about whether to fight. He tells him to use knowledge (jñāna) as a sword to cut through doubt (saṁśaya), which is born of ignorance (ajñāna) and lodged in the heart, then to take up yoga and stand up for the battle in front of him. Traditions differ on whether this yoga mainly means karma-yoga, disciplined action without attachment to its results, or a path in which knowledge of the self is central, as in Advaita readings.