A famous hermit. कठोपनिषद् is the exhortation given by यमदेव (God of death) to this hermit. There is a story to substantiate this statement. The father of नचिकेतस् was the hermit वाजश्रवस् . This hermit gave as alms, cows which had grown lean by old age and lack of food, at the time of sacrifices. नचिकेतस् felt grieved at this action of his father. He went to his father and sadly asked him "Father, to whom are you going to give me?" The father got angry at the question of the son, and replied; "You are to be given to यम ."

On hearing these cruel words of his father, the boy went to the palace of यम who had been away. For three days and nights the boy waited there without food and drink. When यम returned the boy was happy and cheerful and यम was pleased with him. यम promised the boy three boons and asked him what boon he wanted. The first boon he asked for was, "Give me the boon that father will be pleased with me and not angry with me." The second was, "Advise me how to attain heaven." The third was, "Tell me the solution of the mystery, whether the soul remains after death." यम granted the first two boons and said to him, "Boy, this is a difficult question. So ask for another boon such as long life, power over the world, all the pleasures of the world and so on."

The boy replied: "The things you have promised to give me are useless things because after a while the organs of sense will become fragile. The life also will end. So, please tell me. I want the answer to my question." Being greatly pleased at the reply of the boy Dharmadeva expounded to him about the immortality of the soul and the essence of things regarding God Almighty. (Kaṭhopaniṣad) .