Lord Vishnu once performed penance towards Lord Shiva in order to be blessed with offspring. Pleased with this penance, Lord Shiva appeared before Lord Vishnu along with Umadevi and Skand in between them denoting the blessing of progeny. Lord Vishnu was enthralled by this vision and desired to haave it before him always. So he summoned Visvakarma the celestial architect to create a figurine of Shiva Somaskanda (sa-uma-skanda: iti somaskanda). the resultant statue was so beautiful. lord vishnu alwys kept in his heart and offered pujas to it. now visvakarma used no sculpting tool to create this figurine.
One day the devas were troubled by an asura, who threatened indra's position. lord vishnu gave indra this somaskanda statue to indra and advised him to worship it and soon he will be relieved of troubles.and as expected the devas weer restored in devaloka. again as destiny would have it indra was troubled by a terrible asura called 'valaa'. this time indra was powerless. and this asura could be destroyed only by a human. The only one who could do it was muchukunda chakravarti who had a monkey face, but was human by birth. the history of muchukunda is that he was a monkey in his previous birth and without his knowledge playfully he had worshipped a siva linga with bilva leaves on a mahashivarathri night. he was blessed by lord shiva and mother parvati with the position of a monarch in his next birth. Muchukunda requested that he be born with a monkey face so that he will not get lost in worldly pleasures and he may remember lord shiva and his grace on him, and so that he may continue his shiva bhakti.
Now muchukunda helped indra regain his indraloka, and indra asked him what he wanted in return. muchukunda requested for the somaskanda idol as there was nothing like i t on earth and becuse of his shiva bhakti. indra was reluctant to part with the lord and he told that he would give it once he got permission from lord vishnu. lord vishnu approved of it.

Indra then summoned visvakarma and asked him to make six more such statues identical to the original. meanwhile, when muchukunda was asleep, lord shiva came in his dreams and warned him about indra's plans. he said that indra would show him seven idols. however, the one on which the bee sits is the one which lord vishnu worshipped. he should take that one.
When muchukunda came, indra showed him all the seven idols and asked the king to choose one. now, as the lord had told him, a bee swarmed around one idol and sat on it. immediately muchukunda picked that indra was in a fix. realizing his folly, he offered all the seven idols to the king heartily There are seven such temples in South India in Tamil Nadu. They are called 'the saptha vidanga sthalangal'. In Thiruvaroor, it is called 'veedhi vidangar'. Vidangar has different meanings. among them 'one who has swallowed the halahala poison' is one menaing. the other is the 'great lord copresent with uma and skanda'. more interestingly, another meaning: an idol or statue or figurine that has been made without using a scalpel or sculpting tool. ERAIVAN MIGAPERIYAVA ERAIVAN MIGAVUM KARUNAIKONDAVAN