SIGNIFICANCE:
God assumes various forms in pursuance of His Divine Leela. Exactly at midnight on SIVARATRI, He manifested in the form of a formless ISVARA, known as LINGODBHAVAMOORTHI (लिङ्गोद्भवमूर्ति)
In every important Siva temple, one finds a shallow recess (niche) in the outer wall of the Sanctum Sanctorum, exactly behind the spot where the deity is installed. In that niche, we can see a representation of the LINGODBHAVAMOORTHI (लिङ्गोद्भवमूर्ति) a form emerging out of a Linga. In this form of Siva, we can see neither the top half of the head nor the bottom half of the legs. All other attributes of Siva, like the axe, the deer will be found sculptured. We will also find depicted a Swan in flight at the top of the Linga, and a boar, burrowing the earth at the bottom.