Nachiketas was the son of sage Vajasravas. He was unhappy because his father, who had promised to give away everything he possessed after performing a yaga, had sinned gravely. He had given away cows that were weak and were not likely to be of any use to the recipients. So Nachiketas was worried, that because of this, his father would not be able to reap the benefits of the yaga.
The great king Raghu once performed a yaga and gave away all his possessions. The story goes that when a sage went to him requesting 1,000 cows, Raghu ventured out to get the cows. So although he was a king, he had become a pauper by volition, because of his yaga. Vajasravas, having promised to give away all he owned, should have done so, but he had failed to do so. Thus Nachiketas knew his father’s sin was grave. When, therefore, his father angrily said he was going to give away his son to Yama, the God of death, Nachiketas went to Yama’s kingdom willingly. Yama was away when the boy arrived, but the boy would not be turned back and decided to wait till Yama came, and Nachiketas’ resolve was rewarded, said Valayapet Ramachariar, in a discourse.
Nachiketas waited for Yama without food or water. When Yama came in, he was told that a boy was waiting for him, and he seemed to be the personification of Agni. It is a grave sin not to welcome guests and offer them food and water. So Yama was anxious that Nachiketas, who had been waiting for three days with no food or water, should first be shown some hospitality. Yama asked the boy to eat and explained that to keep guests hungry was wrong, and that the Sastras said that even if a guest arrived un-announced and in the middle of the night, he should still be offered food.
But there were other things on Nachiketas’ mind, and he was not worried about food. He wanted answers to his questions. Yama then told Nachiketas that he (Yama) would grant the boy some boons. Nachiketas prayed that his father’s yaga should give him the desired result. Secondly, Nachiketas prayed that his father should no longer be angry with him. Yama granted Nachiketas the boons he sought. Nachiketas also learnt Brahma Vidya from Yama.