Lord Muruga had just been outsmarted by his brother Ganesa in a contest for going who around the world first and He was still smarting over the matter. Ganapati had won the fruit (the yhana-pazham) by simply going around his parents. Long after this, Subrahmanya came seating on his peacock to find that the fruit had already been given away. In anger, He consecrated to leave his home and family and came down to Tiru Aavinankudi at the Adivaaram (meaning 'foot of the Sivagiri Hill'). Siva pacified him by saying that Subrahmanya Himself was the fruit (pazham) of all wisdom and knowledge. Hence the place was called Pazham-nee ('You are the fruit') or Palani. Later He withdrew to the hill and settled there as a hermit in peace and solitude.
Lord Muruga, in His aspect as Lord Dandayudhapani, stands for repudiation. Shunning all wordly possessions, the only apparel He has chosen to retain is a breechcloth . But His bhaktars never tire of offering Him costly garments and enriching His wardrobe with luxurious royal clothes which are used to adorn Him when His devotees yearn to see the Lord in the vesture of a King. For indeed, His state is that of a Swami or self-governing Lord.
It is also claimed by many that the materials of abhishegam like milk, sandalpaste, etc., attain medicative properties on being decanted over Lord Palaniandavars idol and they have healed many diseases, when taken by the patients.
The avatar of Palani Andavar is said to have been made of Navapaashanam ( a combination of Veeram, Pooram, Rasam, Jathilingam, Kandagam, Gauri Pasanam, Vellai Pasanam, Mridharsingh, Silasat), by a siddhar called Bhogar.
Sage Agastya wanted to take two hills - Sivagiri and Sakthigiri - to his abode in the South and commissioned his disciple Idumban to carry them. Idumban bore the hills slung across his shoulders, in the form of a kavadi one on either side. When he was fatigued, he placed the kavadi near Palani to take rest.
At this stage, Subrahmanya or Muruga had been outwitted in a contest for going round the world. Ganapati had won the prized fruit (pomegranate or mango) by simply going round His parents. Long after, this, Subrahmanya came sweating on His peacock to find that the prize had already been given away. In anger, the frustrated child left the divine parents and came down to Tiru Avinankudi at the Adivaram (pronounced Adivaram. It means foot of the Sivagiri Hill). Siva pacified Him by saying that He (Subrahmanya) Himself was the fruit (pazham) of all wisdom and knowledge nee - you. Hence the place was called 'Pazham Nee' or Palani. Later, He withdrew to the hill and settled there as a recluse in peace and solitude.
When Idumban resumed his journey, he could not lift the hill. Muruga had made it impossible for Idumban to make it. In the fierce battle that ensued, Idumban was killed but was later on restored to life. Idumban prayed that:
1. whosoever carried on his shoulders the Kavadi, signifying the two hills and visited the temple on a vow, should be blessed and
2. he should be given the privilege of standing sentinel at the entrance to the hill.
Hence we have the Idumban shrine halfway up the hill where every pilgrim is expected to offer obeisance to Idumban before entering the temple of Dandayudhapani. Since then, pilgrims to Palani bring their offerings on their shoulders in a kavadi. The custom has spread from Palani to all Muruga shrines worldwide.
Bogar is a Siddhar, he is considered as one of the 18 siddhars born in the world. According to epigraphical sources and his book Bogar Seven thousand his period is around 3000 B.C. Bogar born at India and visited China in search of truth of life, he gained knowledge in medicine, astrology, spritiuality, yoga etc. Bogar anticipating that in due course of period, human beings will suffer from large number of disease. As an expert in medicine he used 4448 rare herbs and made 9 poisonous medicine, mixing these 9 poisons into one needs great knowledege and skill, to make a Master Medicine ( One medicine to cure all disease ). Thirumoolar also discuss one such Master Medicine in his book Thiru Mandiram. With the consultation of Agasthiar ( Father of Ayurvedic Medicine) and other siddhars Bogar mixed the 9 poisons ( Nava Bashanam ) and made the Master Medicine in the form of Lord Murugan which is currently worshiped at Palani Murugan temple. There is a place near Palani Hill called Thanasiappan Temple which is the place were Bogar mixed the Nava Bashanam and made the Murugan idol. Bogar and others then decided that by using the milk and panchamirtham ( a sweet recipe ) poured on the idol, one can extract the medicine from the idol. The milk and panchamritham then becomes medicine to cure disease. After installing Lord Murugan Navabashana idol at the Palani Hill, Bhogar used to worship it with milk abishegam ( pouring milk on the idol ) and panchamirtha abishegam ( pouring panchamirtham on the idol ). His disciple Pulipani siddhar then took over the job of Lord Murugan pooja after Bogar went into Nirvigalpa Samadhi - the highest samadhi stage where the Mind dissolves with Matter and Energy.
Bogar Samadhi is inside Palani Murugan temple at Palani Hill. Actually Bogar himself constructed his samadhi exactly under the Lord Murugan Navabasha idol and went into Nirvigalpa Samadhi there. The entrance to his samadhi is a cave like structure, now also worship for this great siddhar is conducted at this entrance where he is last seen by his disciples which is at the Palani temple.