Vyakrapaadar, a Siva devotee, and his wife lived in Pundarikapuram kshetram. Full of knowledge and dispassion he led a simple life. This couple had a son by name Upamanyu. A very quiet boy, even by nature he possessed great virtues such as Kshamai (forgiveness), sathyam (truth), dayai (kindness), shanti (peace). He showed great respect, love and humility towards Sadhus and elders. On the whole he was very virtuous.

The parents conducted his 'upanayanam' and sent him to Maharishi Dhowmiyar Patashala (school) for studies. In this Patashala there were two other students, by name, Uthalagan and Vaidan. Everyday the Guru 'Pathini' (wife of their Guru-teacher) provided only her own children with cow's milk and not the other children.

Once during his visit to his parents, Upamanyu, said to his mother, "Ma, our Guru's wife provides her own children with cow's milk but does not give us. I, too, wish to drink cow's milk. Ma, give me some cow's milk." The mother consoled him, " My child, we are Munis. Tapas is the ornament of the Munis. We should eat only vegetables and roots and not desire for higher things." But the child refused to be consoled and demanded cow's milk. So the mother, to put the child at rest, said, "Well, isn't there a cow in front of Lord Siva? If you pray to Lord Siva you will be blessed with milk from this cow."

Upamanyu returned to the Patashala and completed his studies. Close to Pundarikapuram is situated Sirgazhi also known as Brahmapuram. After completion of his studies Upamanyu went to Brahmapuram and conducted puja to Lord Siva with deep devotion.

Due to his deep faith Lord Siva appeared before Upamanyu. Upamanyu prayed to Lord Siva, "Oh! Lord! Bless me with true knowledge!" Lord Siva said in all kindness, "Child, you performed the puja to obtain milk. Come with me." Lord Siva then led Upamanyu to Lord Narayana who dwells in 'paarkadal' (The ocean of divine milk where Lord Narayana lies on the bed of the divine Serpent Anantha). Upamanyu drank the divine milk, attained 'siddha shuddhi' (purification) and had Lord Narayana's darshan. Lord Siva and Lord Vishnu disappeared.

Even to this day stands the 'ksheerabdhi (milk) theertha (pond)' near the Purushothaman temple in Nangoor Divyadesam, as a sign of this incident.