Parsava or Parsva or Parivartini or Parivartana or Vamana Ekadashi Vrat katha
In Treta yuga there lived a great demon king by the name of Bali. Though he was a demon he was rightful, virtuous, kind and ruled his kingdom as per Dharma. He was very powerful and conquered all the worlds. King Bali plans to perform the Aswamedha Yaga and starts the preparations for the same.
Here Lord Indra is worried that if Bali finishes the Yaga he would loose his throne and Bali would rule. He goes to Lord Vishnu for help. Lord Vishnu expresses his inability to kill a righteous king even though he is a demon. Lord Indra and other gods along with sages try to explain their anguish as to why Bali cannot become the Indra. Lord Vishnu sympathizes with the gods and agrees to stop Bali but will not kill Bali.
Lord Vishnu takes the form a Brahmin boy who is called as Vamana and reaches the place where King Bali is performing the Aswamedha Yaga. King Bali as a part of the Yaga is donating generously to all he Brahmins.
When the turn of Vamana comes, Vamana asks Bali to donate 3 steps which would be measured with Vamanas feet. King Bali looks at the small feet and personality of Vamana and advises him to take acres of land or riches. Vamana refuses and is adamant on taking only the three steps measured with his feet.
Bali agrees and donates the three steps. In the process of donating Bali has to pour water from a pot called kamandalam. Sukracharya the Guru of demons recognizes Vamana as the incarnation of Lord Vishnu and advises Bali against the donation. As Bali doesn’t listen to his advice, he takes the form of a bee and stops the flow of water from the kamandalam.
Vamana understands this and takes a grass and inserts it into the pipe of the Kamandalam, to clear the way for water. This grass injuries the eye of the bee there by forcing it out and allowing the water to flow. Since then Sukracharya has only one eye.
After accepting the donation, the small Brahmin boy Vamana, increases his body size to such an extent that with one foot Vamana covers the earth and with the other step all the other worlds.
He asks Bali where is it that he has to place the third step. Bali immediately without any hesitation shows his head. Vamana pushes Bali to the Patala Loka and moved by his righteousness grants him a boon and stays with Bali as Vamana in Patala Loka.
