Katha Upanishad - Verse 1.3.6
Text: नाचिकेतमुपाख्यानं मृत्युप्रोक्तँ सनातनम् । उक्त्वा श्रुत्वा च मेधावी ब्रह्मलोके महीयते ॥ १६ ॥ nāciketamupākhyānaṃ mṛtyuproktam̐ sanātanam | uktvā śrutvā ca medhāvī brahmaloke mahīyate || 16 || 16. Hearing and repeating the old Nachiketa’s story told by Death, the intelligent man attains glory in the world of Brahman. Shankara’s Commentary: The sruti, for extolling the knowledge treated of, says: Nachiketam ] obtained by Nachiketas. Mrityuproktam ] told by Death. The story] contained in the three vallis....