Janamejeya’s Sarpa Satra
Nag Panchami is related to a story from Mahabharatha.Once upon a time, King Parikshit who was the grandson of Arjuna, had been cursed by a sage to die of snake bite.
Takshaka, the snake king came to fulfil this curse and killed King Parikshit by biting him while he was meditating on Lord Vishnu. King Janamejeya, the son of King Parikshit was enraged and decided to avenge the death of his father by performing a snake sacrifice known as Sarpa Satra. This yagna would wipe out the entire Naga race.
For this great ceremony, a sacrificial fireplace was specially erected. The goal was to kill all the snakes including Taksaka, by dragging them into the fire with the power of the special mantras. Many learned Brahmin sages came to execute this great task!. Janamejeya, himself supervised the ceremony. The yagna was so powerful that it caused snakes from every corner of the world to fall into the Yagna kunda (sacrificial fire pit). It was indeed a horrendous sight!
The sages soon came to know that Takshaka had fled and escaped to the nether world of Indra, to seek his protection. Without losing a second, the chief priest invoked a powerful mantra that would bring both Takshaka and Indra into the fire.
This petrified the Gods who then appealed to Manasa Devi, the Goddess of snakes to intervene and resolve the crisis. She then requested her son Astika to go to the site of the yagna and appeal to Janamejaya to stop the SarpaSatra yagna. Astika impressed Janamejaya with his knowledge of all the Sastras (scriptures). Janamejaya was so pleased that he asked himto seek a boon. It was then Astika requested Janamejeya to stop the SarpaSatra.
The king Janamejeyawas never known to have refused a boon promised to any Brahmin. So he relented and agreed to stop the yagna in spite of the protests by the sages performing the yagna.Thus the yagna was stopped and the lives of Indra,Takshaka and his other serpent race were spared. Indra himself paid homage to Manasa Devi.
This day, according to the Hindu calendar, happened to be Nadivardhini Panchami (fifth day of bright fortnight of the lunar month of Shravana during the monsoon season). Hence this day is known as Nag Panchami. This is a festival of Nagas, as their lives were spared by Astika.
Snakes and Cobras are worshipped on this day by lighting lamps, offering milk, sweets and flowers to them. People pray to the Nagas by chanting the following mantra:
नाग प्रीता भवन्ति शान्तिमाप्नोति बिअ विबोह् सशन्ति लोक मा साध्य मोदते सस्थित समः
From this story, we learn that just like King Janamejeya, we too should fulfil our promise.