A Shiva Yogi named Sundharanaadhar in the elite Disciples of the
Chief Protector of Lord Shiva's abode in Kailasha, known as Nandhi.
Sundharanaadhar had mastered all the eight Great Siddhis (Yogic
Powers). He is part of the Kailasha Generation and studied the
Siddha wisdom under the tutelage of Sri Nandhi. He traveled from
Kailasha to Southern India to visit His close friends.
On the way, He was graced to watch the Blissful Dance of Lord Shiva in the Natarajar Temple in Chidambaram along with great Siddhas such as Patanjali. After watching the dance of Shiva, he reached Thiruvavadudhurai and captivated the beauty of Goddess Parvathi while performing meditation to Lord Shiva. After some time, he decided to leave the place and started on his journey. This is where an unfortunate event took place, a cowherd by the name of moolan died, and the cows were trying to wake him; Sundharanaadhar, the Shiva Yogi, upon seeing this sad scene, decides to help them (cows). So, he did one of the Siddhi (Pragaya Pravesham) (the art of exchanging souls between two bodies) and exchanged his soul with the body of Moolan. This is where the Shiva Yogi took the name Thirumoolar (Respected Moolan). Thirumoolar expounded the Siddhas teachings called Thirumandhiram that have 3000 aphorisms covering a wide field of Divine Knowledge of the Unmanifest and the Manifest creation. His education is based on realizing the Human Body as the Temple of God. Consecrate all Human to Divine. Share Divine Bliss to all Humanity.
The Icon that of Thirumoolar that you see is as per the Direct Darshan of His Holiness during my Tapas in Siddha Sadhana. It was His Golden Light Body State that He has attained. The numbers you see in the icon are the Aphorisms I heard in my consciousness field during His Darshan. I was amazed to know that those songs explained how He had achieved the State of Golden Light Body.
Sadhguru Sri Anbe Arunachalananda