Ribhu was Brahmaa's son and was born in Shwet Varaah Kalp. He was the incarnation of Mrigshring Muni.

There is a story in Vishnu Puraan, Dwiteeya Ansh about Jadbharat, in which he tells the story of Ribhu to the king of Sauveer country. Ribhu had a disciple named Nidaagh - son of Pulastya Rishi. Since Ribhu was very learned in Paramaarth and A-Dwait thoughts, he preached the same to Nidaagh also, but Ribhu knew that Nidaagh could not grasp it.

Nidaagh used to live on a bank of a river. Once Ribhu came to him in disguise of a beggar and asked for some food. Nidaagh got very happy to see him and offere him good food. Nidaagh did not recognize him so he asked him - "Who are you? Where are you coming from? Where will you go?" At this Ribhu preached him A-Dwait thoughts and went away.

Ribhu again came after 1,000 years to preach A-Dwait thoughts to him. At that time he was standing outside the city and waiting for the king to go away inside the city. Ribhu asked, "Why are you standing here?" Nidaagh said - "I am waiting for the King to pass and crowd to become less." Ribhu asked - "Who is the King and who is the elephant?" Nidaagh said - "Who is sitting up on the elephant is the King, and who is below the King is the elephant." At this Ribhu asked - "Who is up and who is below?" Hearing this Nidaagh climbed up on Ribhu and said - "See, Now I am the King who is up, and you are the elephant who is below."

Ribhu asked - "Then who are you and who am I?" Hearing this Nidaagh fell on Ribhu's feet saying, "You cannot be anybody else than my Guru who is profoundly knowledgeable in A-Dwait thoughts." Ribhu said - "I just came here to preach you this that this whole world is different forms of Vishnu only, nothing else." And Ribhu went away. Nidaagh also went to his home.