He got his name because a gigantic modhakam is given as an offering to him on the Vinaayakar Chathurthi Festival.
This moOdhakam is made with 3 kuRuNis of rice.
A kuRuNi is a type of measure. It is equivalent to 4 padis. MukkuRuNi is 3 X 4 = 12 padis of rice.
12 measures of rice is taken and cleaned well with water. Then it is soaked. It is then pounded in a 'ural' - mortar. The flour is mixed with gram, coconut, cane sugar, salt, cardamom, etc. It is then moulded and wrapped in a cloth and made into a bundle. It is then steamed in a giant 'kopparai' - steamer which was made especially for this purpose. When appropriately cooked, it becomes a gigantic 'MOdhakam'.
The MukkuRuNi Vinaayakar is said have been found in a place called VaNdiyuur.
Tirumalai Nayakkar wanted to build a very beautiful and huge Palace for himself in Madurai. So he procured large plot of land which occupied the south-eastern sector of the Madurai city within the confines of the fortress. 'Procure' means 'just take'.
The construction of the palace needed a lot of suitable soil, earth and sand. A site where all these could be found was chosen. It was near the VaNdiyuur Mariyamman Temple. The river Vaigai flowed very near the site. The site itself has been traversed by the River Vagai and had been a river bed on and off.
The evacuation of large amount of earth in that place caused a huge pit.
Thirumalai converted this pit into a beautiful tank with a central islet.There he built with a beautiful mandapam and vimanam with four smaller mandapams with towers. This is the famous 'Maiya MaNdapam'.
During Thaipusam, the Thappa Thiruvilza takes place.
SriMeenakshiSundaresvarar are placed in a giant raft and taken around the full tank.
While the digging was taking place, the diggers found a giant statue of Vinaayakar.
Inside the Meenakshi Temple Complex, there is the sannidhi of SriSundaresvarar.
The SriSundaresvarar shrine faces towards the east.
Just to the northern aspect of the SriSundaresvarar shrine, there is 'VeLLiyamabalam'. This is the shrine of Nataraja perfromig the Cosmic Dance. The Dancing Nataraja is said to perform his Cosmic Dance in five places. They are known as the 'Sabha's. The sabha at Chidhambaram is the Golden Sabha or 'Pon Ambalam'. Madurai is the 'Silver Sbha' - 'VeLLi Ampalam' or 'Rajitha Sabha'.
Normally, the Dancing Nataraja stands on his right leg and throws across the left leg. According to the ThiruviLaiyaadal puraaNam, there was a Pandya king who was grief-striken because of this. He felt that Nataraja has been standing on his right leg for eons of time. He prayed ardently to Nataraja to shift his stance and change his posture. He wanted to Nataraja to stand on His left leg and life up and throw across His right leg.
Because of his prayers, Nataraja appeared and hearing the Pandya's plea, shifted his legs. He stood on his left leg and lifted his right leg and danced thus.
This is known as 'Kaal maaRi aadiya patalam' among the 64 ThiruviLaiyaadal's - 64 Divine Sports of SriChockanatha Peruman of Madurai.
The shrine of Nataraja in the VeLLi Ambalam faces south. It is straight in line with the gateway of the Southern Gopuram. Outside the southern gopuram is the Chokkappa Naayakkan Street which led to the TheRku Vaasal or the southern entrance to the fort of Madurai - Madurai kOttai.
VeLLi Ambalam is a very powerful node of Cosmic Power. The power gets enhanced with the performance of Manthra recitation and prayers. The overflow of power takes place once in a while in regular intervals. This outsurge of the Cosmic Energy may take the form of certain manifestations . Usually it would be in the form of fire. Certain areas used to catch fire because of the outsurge of Cosmic Energy. This was known as the 'Paarvai'.
So they closed up the door which opened directly towards the VeLLi Ambalam. Outside the newly built walled up section, they built a large alter. This alter faced south.
In this alter, they housed the large PiLLaiyaar who was found in place where they were digging for earth for the palace.
Special types of worship were instituted for the PiLLaiayar. Fragrant smoke from incence like Benzoin - SaambiraaNi was continously produced. Special offering with kolzukkattai or mOdhakam from 3 three kuRuNis of rice was made.
Thus the famous MukkuRuNi PiLLaiyaar of Madurai Meenakshi Temple became established and worshipped.
This story was narrated to me by the great scholar Dr.A.V.Jeyachandrun, the creator of the Temple Art Museum of the SriMeenakshi Amman Temple.