According to legends,  Lord Shiva entrusted sage Agastya with two hills, the Shivagiri Hill and the Shaktigiri Hill, with instructions install them in the present day Southern India. The sage left them in a forest and later asked his disciple, Idumban, to get them. Idumban found the two hillocks, lifted them with great difficulty but put them down near Palani – the now famous shrine of Murugan. When he attempted to continue his journey, he found that the hillocks were immovable. Idumban sought the help of a youth, but the youth claimed the hillocks belonged to him. In the ensuing scuffle, Idumban was defeated. Idumban then realised that the youth was Lord Murugan.

Seeking forgiveness form the Lord, Idumban prayed anyone carrying the kavadi – signifying the two hills – and visiting the temple on a vow should be blessed abundantly and that He (Idumban) should be given the privilege of standing sentinel at the entrance to the hill. To this day, devotees pay obeisance to the shrine of Idumban before entering the Palani temple with the kavadi.  The custom of kavadi spread from Palani to all Murugan shrines worldwide.