Uma once closed the eyes of her husband Maharudradeva in a playful mood. She came from behind and closed his eyes. Although it was only for a few minutes, the entire universe was submerged in darkness for years. This was a wonderful way for Maharudradeva to make his consort in particular and everyone of us in general understand that everything that is inside him is also outside, and everything that is outside is also inside him. Uma realising that a small fun she played with Paramaguru had left the whole universe without light. She requested him to restore light. Then Shiva appeared as a AGNISTAMBHA (column of fire) with neither the base not the plinth. The column was so vast that none knew where it started and where it was going to end. Just a huge column of fire appeared at a place called Thiruvannamalai. The column of fire brightened the universe.
Maharudradeva had manifested as Agni. Agni Tattva is one of the five elements. The fire element is the storehouse of illusions relating to name and fame, issues related to power, authority and control over others, wealth and longevity vs poverty and death. Agni is the one and only element of all the five elements (Earth, Ether, Water, Air and Fire) that cannot be adulterated. Agni will burn anything which is put into it in an intention to pollute or adulterate it. We can pollute or adulterate anything but not fire.
The manifestation of Maharudradeva as Agni Tattva is commemorate even today at Arunachalagiri. On Karthika Pournami a huge lamp is lit on the top of the hill.
Arunachaleswara is Tejo Linga. When the light on the top of the Tiruvannamalai is unveiled on the Karthika Pournami day people pray to Shiva in the form of fire.
The esoteric symbolism behind lighting the lamp on the hill is to have the vision of the light of lights that is burning eternally in the chambers of ones heart through constantly remembering the Paramaguru and be ready to receive his guidance.
The light if lights annihilates the three impurities - egoism, selfish action and delusion. The eternal light in the cave of the heart burns the mind, senses and the desires. To attain full illumination and behold the light of lights is real Kartikha Deepotsava.
May the light of lights illumine all of us from within! May Lord Shiva bless us with abundant light! May we all merge in this supreme light and attain the eternal abode of bliss and immortality!