Tirunavakkarasar, Appar

Tirunavakkarasar, known popularly as Appar, one of the four Samayacharyas.

Image of Satguru Sivaya Subramuniyaswami
One who performs japa properly will realize what he knows. You see, japa opens up the inner mind and focuses the energies of certain chakras, which are consciousness encased within the psychic nerve ganglia of the nadi network.