Lord Shiva who came to the rescue of Brahma, questioned his little son's authority to imprison the God of creation; he wondered whether Skanta knew anything about Om. Skanta, the little master was bold enough to tease his father that if Lord Shiva too didn't know the meaning of Om, he could very well learn from him, provided he came to him very politely, like an earnest student who wants to learn from his master.
Lord Shiva agreed at once. Like an obedient student, he sat low in front of his son, with one hand close to his chest and the other hand closing his mouth (this is a traditional way of showing respect to Guru and Saints). Skanta then expounded the secret behind Om secretly in the ears of Lord Shiva.
Since Skanta thus became a saint who taught to the very lord of the universe, he was called Swaminathan. In Tamil, he is hailed as "Thagappan Sami" - one who became a Guru to his own father.
So that Tamils believed him to be supreme of all gods due to this incident .
Since Lord Skanta settled himself in Tamilnadu after the controversial fight over the wisdom fruit with his brother ,he relocate himself ,by addressing, "My People My abode " (this touched Tamils very deeply ) over Mount Palani.
Lord Skanta Features mystically relates with Tamil language...
Skanta having 6 heads =Language Tamil having classical sounds or nasals letters 6 in number.
Skanta having 12 Hands = Tamil Language having Soul letters or vowels 12 .
having in total 6 heads + 12 hands = 18
where in Tamil language Body letters or consonants are 18 etc .
He is called as "Yentra tantra mantra" personality by Tamil siddars are sages .This Mystically related to the meaning that, god who dwells in sounds and he who is the gate way for attaining Gyana .
So commonly they said ,sounds of Tamil language is the form of Lord Skanta ...So the famous divine poet as well as sages like Arunagirinather , Nakirar works having strong sound based songs equal to sanskrit mantras.
According to the Tamil sangam records orderly Lord shiv , Lord Skanta , sage Agastya , Lastly poet Nakkirar are Head of the 3 well known Tamil Sangams.
Tamil Sangam : There are Three sangams(assembly of learned persons ) held in tamil land, where two of it is held in the drowned surface or said to be continent called Kumari kandam (Lemuria of indian ocean )
First Sangam: Founder and Head is Lord shiv (he is called Iraiyanaar).in South madurai..belongs to that Mystic Continent .But according to their records the city is said to drowned due to a great tsunami.
Middle or Idai Sangam: The pandiyan kings relocate the sangam to Kapadapuram (the remaining land of SouthMadurai),where Lord Skanta Presented himself as head of that Sangam.Later Sage Agastya too succeeded after him .The Famous Tholkapiyam belongs to this period .But this sangam and city too came to end after a Tsunami.
Third or Kadai Sangam : This is the Last Sangam held in North Madurai (Present city far away from sea shores).
Hence Lord Skanta is not different from Lord shiv but a younger version of him
So he himself volunteered for the Development of this language is the reason behind the Words" Patron god of Tamil Language ".
you can refer about sangams here since they are experimental theories they never mentions about Gods...
t Virisadaik Kadavul".
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