King Swetakethu, of the Ikshvaku dynasty—chosen by Lord Sri Rama for His incarnation—was renowned for his honesty and integrity. He, along with his wife Damayanthi, had a deep desire to visit Vaikunda and have the darshan of Lord Vishnu. After fulfilling all his royal duties, Swetakethu prepared for penance with his queen by setting up a fire around them and standing in the sun. They endured this severe penance for days, ultimately shedding their mortal forms and reaching Vaikundam. However, they were unable to find their Lord Vishnu and felt disheartened.
Sage Narada appeared before them. When Swetakethu and Damayanthi sought his guidance on why they failed to see the Lord, Narada explained that despite their severe penance, they had neglected essential rituals such as small Homas and charitable acts. He advised them to worship Lord Iravadeswarar on the banks of the Cauvery River on Earth and seek His aid to gain the darshan of Lord Vishnu.
Following Narada's advice, the couple prayed to Lord Iravadeswarar, seeking His help. Lord Iravadeswarar, who also longed for the darshan of Lord Vishnu, agreed to join them in penance. Sage Udanga Maharshi also participated in this collective penance.
Eventually, Lord Vishnu appeared before them along with the goddesses Sridevi and Bhoodevi. At this moment, Lord Iravadeswarar requested that the place where they received the divine darshan be honoured as Vaikunta Vinnagaram, with Himself worshipped as Vaikunda Nathar. Thus, Lord Vishnu graced the location as Vaikunda Vasan, with Mother Sridevi revered as Vaikundhavalli.