Linga means mark, in Sanskrit. It is a symbol which points to an inference. When
you see a big flood in a river, you infer that there had been heavy rains the previous day. When you see smoke, you infer that there is fire. This vast world of countless forms is a Linga of the Omnipotent Lord. The Shiva Linga is a symbol of Lord Shiva. When you look at the Linga, your mind is at once elevated and you begin to think of the Lord.
There is a mysterious power or indescribable Sakti in the Linga, to induce concentration of the mind. Just as the mind is focussed easily in crystal-gazing, so also the mind attains one-pointedness, when it looks at the Linga. That is the reason why the ancient Rishis have prescribed Linga for being installed in the temples of Lord Shiva.
Shiva Linga speaks to you in the unmistakable language of silence I am one without a second, I am formless. Pure, pious souls only can understand this language.
A Shiva Linga consists of three parts, the lowest of which is the Brahma-Pitha, the middle one, the Vishnu-Pitha and the uppermost one, the Shiva-Pitha.
There are twelve Jyotirlingas and five Pancha Bhuta Lingas in India.
The twelve Jyotir-lingas are
Kedarnath, Kasi Visvanath, Somanath, Baijnath, Ramesvar, Ghrusnesvar, Bhimasankar, Mahakala, Mallikarjuna, Amalesvar, Nagesvar and Tryambakesvar.
The five Pancha Bhuta Lingas are
Kalahastisvar, Jambukesvar, Arunachalesvar, Ekambaresvar of Kanjivaram and Nataraja of Chidambaram.
The Linga is like an egg. It represents the Brahmanda (cosmic egg). Whatever that is contained in the Brahmanda is in the Linga. The whole world is the form of Lord Shiva. The world is a Linga. Linga also is the form of Lord Shiva.
Linga means the place of dissolution for the world and
all beings. It signifies also Satya, Jnana and Ananta; Truth, knowledge and Infinity. It indicates that Lord Shiva is endowed with all-pervading and self-luminous nature. Linga is a symbol which makes us understand the various kinds of Artha which are indicated above. There are six Lingas, viz., Anda Linga, Pinda Linga, Sadasiva Linga, Atma Linga, Jnana Linga and Shiva Linga. These Lingas are taken to mean the characteristics by which the Anda (the Universe), Pinda (the body), Sadasiva, etc., are to be recognised and understood.
Spatikalinga is also a symbol of Lord Shiva. This is prescribed for Aradhana or worship of Lord Shiva. It is made up of quartz. It has no colour of its own, but takes on the colour of the substances which come in contact with it. It represents the Nirguna Brahman or the attributeless Supreme Self or formless and attributeless Shiva.
Lord Rama worshipped the Shiva Linga at Ramesvar. Ravana worshipped the golden Linga. What a lot of mystic Sakti there should be in the Linga!
In Sanatkumara-samhita of the Shiva Purana, Lord Shiva says O Parvati, daughter of mountain, there is none dearer to Me than the man who worships Me in the Linga, knowing that Linga is the root-cause of everything and knowing the world to be Linga-maya or Chaitanya-maya