The dialogue between the boy Nachiketa and Yama, lord of death, on the nature of the Self — one of the tradition's most vivid and directly narrative philosophical texts.
कृष्ण यजुर्वेद के अंतर्गत · within the Krishna Yajurveda
Nachiketa, given away by his father in a moment of anger, arrives at Yama's door and waits three days unfed; Yama, to make amends, grants him three boons, the third of which Nachiketa uses to ask what happens to a person after death, a question Yama initially tries to deflect with offers of wealth and long life before relenting and teaching him directly.
The Katha Upanishad's chariot analogy, the body as chariot, the intellect as charioteer, the mind as reins, and the senses as horses, remains one of the tradition's most quoted images for self-discipline, and its teaching that the Self is never born and never dies is echoed almost verbatim in the Bhagavad Gita's second chapter.