Sri Oppiliappan Puranam
Mrikandu Maharishi's son Sri Maarkandeyaa worshipped the Lord and desired that lakshmi should appear as his daughter and the Lord should become his Son-in-Law.
When he was doing theerththaadanam
and shethra yaaththirai,after reaching ThiruvinNagaram, he felt that this was the right place for getting his desire fulfilled.
Maarkandeyaa then started a severe penance for 1000 years seeking Lakshim devi's blessings.After he thousand years of penance, Lakshmi appeared as a baby under the already incarnated thulasi chedi (thulasi plant).
Sri Maarkandeya felt the presence of Lakshmi as the incarnation of the baby and realised that one part of his desire had been fulfilled. He took possession of the baby and brought her up.When this young girl reached the adolescent age or paruvam,one day (panguni month sravana nakshathram)the Lord, appeared as an old man and asked for the hand of maarkandeya's daughter.
Maarkandeya replied "You are very ripe and old, my daughter is very young and she does not even know to cook with proper salt (lavanam) contents.You may get angry and curse her if she cannot cook properly.To which the old man replied, "If your daughter must cook without salt, then I will still take it as my best food, but I will not leave from here without marrying her."Without knowing what to do , Maarkandeyaa sought the help of the ever protecting Lord Vishnu.It was then that he realised, using his thabovalam, that the old man was none other than Lord Vishnu Himself.
When he opened his eyes the Lord appeared in front of him with changu and chakram as in SriVaikundam and maarkandeya asked for forgiveness. Sri maarkandeya then offered his daughter's hand in marriageand performed the kannikaathaanam of his daughter (Lakshmi) to the Lord Himself. Since the Lord had said "I will accept the food that is not salted as my best and most desired food", this temple neyvethiyam is always done without salt in any food.
The name oppiliappan is as result of this puranam. However, nammaazhwaar called him "than Oppaarillappan", that is He is the one who has no comparison (i.e. there is neither an equivalent nor superior to this Lord - mikaiyum oppum illaathavan ).