The word Linga is used in the Vachanas at least in three senses, denoting Parashiva or his emblem, Ishtalinga [ಇಷ್ಟಲಿಂಗ], or the Linga established in the temples. The Vachana-writers maintain that the Sanskrit word literally means 'cause' and since Parashiva is the cause of creation, maintenance and destruction of the world, he is called Linga. In the context of the Vachanas the term ‘worship of Linga’ may mean either the worship of Ishtalinga or worship of what it symbolizes, Parashiva.
The practice of worshipping the Lingas established in the temples seems to be older then the practice of worshipping the Ishtalinga. Historians and scholars are of the opinion that in ancient times, merchants were carrying miniature Lingas, which they worshipped on their journey called Chara-Linga [ಚರ ಲಿಂಗ], and later this gave rise to what is now called Ishtalinga. The latter is a miniature Linga covered with mixture of some substances, which make it appear black and shining. But there are two outstanding differences between the sthāvara-Linga (the Linga established in temples) and Ishtalinga.
(a) The sthāvara-Linga, which is established in a temple, cannot be worshiped always or anywhere else. Those who want to worship or witness worship have to go to the temple only; whereas a Lingavanta can worship his Ishtalinga anywhere he likes.
(b) Normally, a priest appointed to worship sthāvara-Linga alone should worship it at particular point of time. Others cannot worship it and are not even eligible to worship it if they belong to lower castes. Women, even if they are Brahmins, are forbidden to worship Linga (or any idol) established in temple; but people of lower castes and women can witness the worship from a distance; whereas any Lingayat can worship the Ishtalinga, irrespective caste and sex.
Ishtalinga can be offered by a guru to anyone who is desirous of Lingānga-sāmarasya, [ಲಿಂಗಾಂಗ ಸಾಮರಸ್ಯ] the highest spiritual goal; and the recipient need not be a Lingayat. But once he undergoes initiation (DĪKṢĀ [ದೀಕ್ಷಾ]) he must practise all Lingayat instructions given by the guru. Moreover, only a Lingayat guru is eligible to offer Ishtalinga. Even the guru who offers it must be one who has attained mōkṣa [ಮೋಕ್ಷ] and it is not enough if he knows the beliefs and practices of Lingayathism.
The initiation of offering Linga presupposes the Lingayat metaphysical doctrine that the top of the brain and the region between the eyebrows are the centers of consciousness (cit), otherwise called, respectively, ājñā-chakra and sahasrāra-padma. The guru as a part of the initiation places his palm on the top of the skull (mastaka) [ಮಸ್ತಕ] and extracts, as it were, the consciousness that is there and establishes it in the Ishtalinga. This act is called hasta-mastaka-saṃyōga [ಹಸ್ತ-ಮಸ್ತಕ-ಸಂಯೋಗ]. Henceforth the Linga is an emblem of Parashiva, and becomes eligible for worship. The initiate is advised against treating it as a piece of stone. To tie it to a part of his person is to think that Parashiva is always with him. This may remind him always that he should be attentively religious and moral.
Actually, as the devotee progresses spiritually, Ishtalinga becomes not merely an object of worship, but a means of concentration. According to Vachana-writers, realizing Parashiva by worshipping and meditating on Ishtalinga should be the goal of a Lingayat.
Many Vachana-writers believe that it is equal to one's own prāṇa [ಪ್ರಾಣ] (life principle) and losing it by chance is equal to losing ones life. In fact, those who lost their Ishtalinga were advised to end their life. But, according to many Vachana-writers, one who lost his Ishtalinga should procure a substitute from a Lingayat guru, rather than committing suicide.
Perhaps the credit of offering Ishtalinga to non-Lingayat through the guru with a view to converting them goes to Basavannaa. The idea behind such a conversion was to proclaim that the right to worship was not the privilege of a few, but was everybody's right. It also implied that all those who wear Ishtalinga were equal and there should be no discrimination among them on the basis of profession or sex.
The word literally means “one who is convinced that Linga (Parashiva) enjoys through the devotee’s body". One who surrenders his all including his senses, internal instruments (antaḥkaraṇa [ಅಂತ:ಕರಣ]) regards his body as just an instrument by which Parashiva enjoys.
|Linganga-Samarasya [ಲಿಂಗಾಂಗ ಸಾಮರಸ್ಯ]||Kundalini [ಕುಂಡಲಿನಿ]|
 From the book "Vachana", pub: Basava Samiti Bangalore 2012.