Now here is the i nteresting part , this pillar was not an ordinary column of fire, it was the Supreme force of Lord Shiva himself, being beyond the limitations of form, color and all other qualities, also having no beginning and no end ! The two Gods set out on their strength to explore the endings the column of fire ut it went on and on only till infinity ! They soon realised that it was futile to look for the end , and as time went on they became more and more tired . Lord Vishnu returned back realizing that it should be the great Lord Shiva having no limits tor boundaries which can ever be measured by all available knowledge,
This then made them realise the truth as to who is actiually the greatest .Lord Vishnu accepted his failure. at that very moment , and Lord Brahma on the other hand, though realizing it is impossible to see the top of the fire column, returned back saying that he had seen the tip of the column, and since his lie stood exposed he is not till day worshipped. Now both of them realizing the greatness of the Supreme power of Lord Shiva, the Gracious one, with lots of devotion and sincerity, started worshipping him.
The Lord out of his grace blesses all the souls in a way they can easily understand and in turn worship the Supreme, Power of Lord Shiva which can not be put into mere words since it is unexplainable, and unexplorable, and appears as a Lingam which is a vertical pillar resembling the flame. As it resembles the flame, iti s neither a form nor a formless, but is just a symbol of the Supreme jyoti. The Lord later appeared in a special form and blessed both Vishnu and Brahma
This form which came out of the formless Supreme out of Its grace to bless the sincere worship of Brahma and Vishnu is a form but represents the formlessness of the Supreme Lord Shiva , and is considered to be very holy by the shaivites ( worshippers of Lord Shiva ) . The shiva lingam (meaning symbol of shiva) is the foremost of all the symbols of Lord Shiva which are worshipped by the shaivites. And much in a similar way as the ashes are closely associated with the fire, the Holy Ash is associated with this Fire pillar signifying Lord Shiva and is considered to be most sacred by all the worshippers of Lord Shiva ! the shaivites.