This was the location that was selected by Sage Subrabar after much searching for an ideal spot to conduct a Yaga to propitiate Lord Vishnu. When he dug the earth here he found an Arrow and Balancing Scale. They turned into a man and a woman respectively. They were a celestial couple cursed By Kubera, the lord of wealth, for an inappropriate act of embracing each other disregarding his presence. They bowed to the Sage, paid respects, and went on their way. The Yaga went on well and Lord Vishnu appeared to bless the Sage and his followers. Since a Balancing Scale (Thulai in Tamil) and Arrow (Vil in Tamil) were blessed to revert back to their married life this place was called Tholai Villi Mangalam. Further, the Lord was requested to stay on here as Devapiran by the Sage.
Ashvini Devas who used to provide medical services to people, desired to receive equal benefits of a Yaga similar to Devas. They were advised by Brahma to go to earth and take a bath at the Theertham here and worship Lord Vishnu in the two temples here to get their desire fulfilled. They did so and Lord Vishnu granted them the boon of equal share.

Vibeedhagan, one of the sons of Sage Sathyaseela in the Himalayas was afflicted with leprosy. His brothers tried every medication unsuccessfully and sought Sage Narada’s advice. Narada said this is due to the act of stealing a cow belonging to his Guru, thus incurring his curse in his previous birth. The solution was to go to Thirutholaivillimangalam and have a bath at the Ashvini Theertham. Vibeedhagan did so, worshiped the lords here at Devapiran Thirutholaivillimangalam and Aravindalochanan Thirutholaivillimangalam, and was cured.