Bharata told the king the story of Ribhu and Nidagha.
The sage Ribhu was Brahma’s son. He was also extemely learned. Nidagha was Ribu’s disciple. After Ribhu had taught Nidagha what there was to be taught, Nidagha went to live in a city. After a thousand years had passes, Ribhu went to the city to see how Nidagha was getting on. Nidagha worshipped his teacher and gave him all sorts of things to eat. After Ribhu had eaten, Nidagha asked him, “Are you satisfied?” “What do you mean?,” asked Ribhu. “The question of satisfaction would have arisen had I been hungry or thirsty. I am my atman and the atman is always satisfied. So what is the point of asking me that question. I am part of the brahman that is omnipresent and so are you. You are not distinct from me, we are both part of the same whole. I came to teach you this knowledge. Now that you have learnt that the brahman is everywhere, let me leave.” After another thousand years had passed, Ribhu came to the city again and discovered that Nidagha no longer lived in the city. He had begun to live on the outskirts of the city. “Why have you given up living in the city?,” Ribhu asked Nidagha. “Because I do not like to live in the city, where there is a king,” replied Nidagha. “Who is the king?,” asked Ribhu. “Point him out to me in this procession that is passing. And point out to me the subjects.” Nidagha said, “The king is the one who is as tall as a mountain peak. He is the one who is riding the elephant. The ones who are walking are the subjects.” “What do you mean?,” asked Ribhu. “The brahman is in the king and the brahman is in the elephant. How do you distinguish one from the other, how do you say that one is riding the other? Is the king the physical body or the atman? Who is riding on whom? I do not understand.” This knowledge, that the atman is the same as the brahman, is known as advaita (unified) brahma-jnana. Ribhu taught this to Nidagha and Bharata taught this to the king Soubira. This is the knowledge that all elements are one and the same. It is only those who suffer from illusions who think that different elements and different beings have different identities. >From Agni Puran SAIRAM
