"How can one know thus as to where It (the Self) is, for which both the brāhmaṇa and the kṣatriya become food, and for which Death takes the place of a curry?" Namaste 🙏 So this is the close of the second chapter, the second Canto of this Upaniṣad, which has six Cantos in two parts. The first Canto was about setting the scene, creating a context where this wonderful conversation between death and Naciketā could take place. Naciketā is not going to take anything other than the highest knowledge. He doesn't want any material benediction. So in the beginning of the second Canto, Death accepts Naciketā as his student and begins to teach him about Brahman. Because really, what Naciketā wants is to know Death's secret.

“This Self cannot be known through much study, nor through the intellect, nor through much hearing. It can be known through the Self alone that the aspirant prays to; this Self of that seeker reveals Its true nature. One who has not desisted from bad conduct, whose senses are not under control, whose mind is not concentrated, whose mind is not free from anxiety about the result of concentration, cannot attain this Self through knowledge.“

“While sitting, It travels far away; while sleeping, It goes everywhere. Who but I can know that Deity who is both joyful and joyless? Having meditated on the Self as bodiless in the midst of bodies, as permanent in the midst of the impermanent, and as great and pervasive, the wise man does not grieve.“