Lingodbhava Murthy or the legend of Shiva Linga is highly related to Maha Shivaratri. It reveals the story about the search done by brahma and Vishnu to search the aadi (beginning) and the antha (end) of lord shiva. Lingodbhava Murthy thus proved to be the supremacy of Lord Mahadeva above all the other gods and tells why the lingam is one of the most potential emblems of the hindu ideals. Three puranas are being used to state the story which are the kurma purana, the vayu purana and the shiva purana.
Shiva Linga Legend:
As per the written statements in puranas, there was a time when there are two triads of the Hindu, as the Puranas go, God Brahma and God Vishnu once got into an argument on each other's powers. When the fight was intense other Gods worried and sought Lord Shiva’s help. To show them the futility of their fight Lord Shiva took the form of a flaming Linga in between the both Gods and challenged them to measure the gigantic phallic symbol of Lord Shiva.
Awestruck seeing the magnitude, Lord Brahma and Lord Vishnu decided to find one end each to prove their powers, taking the forms of a swan and Varaha (a boar) respectively. Neither could find the end even after traveling thousands of miles.
Exhausted and bewildered with his search to find the uppermost limit of fiery column Lord Brahma made flower Ketaki to lie that he had seen the top of the column where the flower had previously resided. Later, he confronted Lord Vishnu and shared his success in finding the origin of cosmic column. Right then, Lord Shiva pierced himself out of the central pillar revealing his omnipresence. Surrendering to the glorious sight both Brahma and Vishnu bowed to the Supreme soul accepting the greatness. Lord Shiva explained how both Brahma and Vishnu were born out of him and the three were separated into different aspects of divinity.
Agitated by Brahma’s false claims, Lord Shiva cursed him that nobody would ever pray him. This why there are hardly any temples of Lord Brahma. Ketaki flower was also punished for falsely testifying and for supporting the lie. Lord Shiva banned her from being offered to any God for worship.
It was the 14th day in the dark fortnight of Phalguna month, Lord Shiva manifested himself in the form of a Lingam for the first time. Thus, the day is extremely auspicious and is celebrated as Maha Shivaratri (The grand night of Shiva) ever since. On this special day, devotees fast during the day and pray that throughout the night for prosperity and happiness.
Shiva Linga and its Physical Shape:
Physically, the Shiva Linga in this context is quite different from that of Hindu tradition. It is an egg-shaped stone of brown shades that is gathered from the Narmada River in the sacred Mardhata mountains. Polished to a high sheen, locals sell these stones to spiritual seekers all over the world. They can vary in size from one-half an inch in length to several feet. The markings are said to represent those found on the Lord Shiva's forehead.
Those who use the Shiva Lingam see in it a symbol of fertility: the phallus representing the male and the egg the female. Together, they represent the fundamental creation of life and of Nature itself as well as a fundamental spiritual balance.
The Lingam stones are used in meditation, carried with the person throughout the day, or used in healing ceremonies and rituals.