The story of the birth of this zoomorphic deity, as depicted in the Shiva Purana, goes like this:
Once goddess Parvati was alone at house and wanted to take bath. So taking the dirt from her body she created a boy and ordered him. "Keep a watch at the door, and don't allow anybody to enter the palace without my permission." Thus instructing the boy. Mother Parvati went in to take her bath.
Meanwhile Lord Shiva too arrived at the scene. He saw a boy sitting at the doorway, but ignoring him he proceeded to enter the palace. At that the boy stood up and stopped Lord Shiva and said, "My mother has instructed me not to allow anybody to enter the palace without her permission. Hence, I will not let you enter the palace. First tell me who are you?"
Instead of answering, Lord Shiva asked, "Who are you? Who is your Mother?"
As no one was eager to answer first so the dispute grew to the point of a fierce battle. Ultimately cutting the head of the boy, Lord Shiva entered the palace.
Seeing Him, Parvati asked surprisingly! "How did you enter? Nobody stopped you?" At that Lord Shiva asked, "Who was that boy? I have cut his head!"
Hearing this, mother Parvati began to cry and said, "He was my own son. Now you give him a new lease of life"
Lord Shiva then ordered his squad (Ganas) to go out and bring the head of any creature that was sleeping with its head facing north.
It was an elephant that the Ganas found sleeping facing north. So they cut its head and brought it to Lord Shiva.
Putting the elephant head at the boy's torso, Lord Shiva infused a new lease of life in him.
Thus, Ganesha got the head of an elephant and came to be known as Gajanana. Ganesha one with an elephant head.
Shiva also made him the leader (pati) of his troops. Hence his name 'Ganapati'.
Shiva also bestowed a boon that people would worship him and invoke his name before undertaking any venture.
Now, let us see at this incidence logically what could be the purpose of fixing an elephant's head on a boys torso?
This preaches the common people that they should not meddle in others affairs. Such an attempt leads to the loss and nothing more. The softest organ of an organism in his testes. Unlike other animals testes of an elephant are located in the head, which is also known as Gandasthala (temples). It is the softest spot in otherwise hard and huge body of an elephant.
Hence, an elephant does not put his head against anything. Thus it preaches the others to do the same. To get this preaching across the people, Lord Ganesha is shown with an Elephant's head.
Elephant head of Ganesha and Brahmajnana:
Every Hindu knows how angry Shiva chopped off the head of his son Ganesha and later replaced the head with that of an elephant.
We can know why head of an elephant was selected, through Brahmajnana.
The unique feature of Ganesha:
Ganesha symbolizes the mechanism which enables us to divert power of unwanted activities into the task we are performing with very little power.
The mechanism also adds and removes Vighnas or obstacles.
All these need immaculate timing.
- To add an obstacle we must make two activities come at precisely the same time.
- To remove the obstacle we must make the two come at different times.
- Diversion of power from one activity to another too needs precise timing.
The selection of elephant's head:
To introduce a Vighna we must anticipate the arrival of the first thought and then make the second thought (Vighna) come at precisely the same time. Since our prediction wouldn't be precise, we need correction of timing at the final moments.
The head of the elephant symbolizes the Vighna we are using to block an unwanted thought. The trunk of the elephant symbolizes our final adjustments to the timing of Vighna.
Ganesha automatically adds or removes Vighna, which ever is more appropriate and with great precision, and diverts power to the better activity.
Thus, elephant head is selected for Ganesha because it has more maneuverability than the head of any other animal.