There was an Asur named Gayaasur. Once it so happened, that Gaya named Asur did severe penance here. Devtaa got scared from his penance and came to Vishnu and said - "Bhagavaan, Please protect us from Gayaasur." Vishnu went to Gayaasur and asked him to ask for any boon. He said - "Prabho, I should be the holiest Teerth among all the Teerth." Bhagavaan said, "So be it." and disappeared.

Now all people went to him to have his Darshan because he was the greatest Teerth. Earth became without people because all people went to Vishnu's Param Dhaam after having his Darshan. Brahmaa and Devtaa again went to Vishnu and said - "Prabho, Prithvi and Swarg have become without people, because everybody has gone to your Lok by having only that Daitya's Darshan." Hari said - "You go to Gayaasur and ask him to give you his body to perform Yagya." Brahmaa Jee went to Gayaasur and asked him for his body to perform Yagya.

Gayaasur said, "So be it." and he immediately lay down on the ground. Brahmaa Jee started his Yagya on his forehead. When the time came for Poorn Aahuti, Gayaasur got scared and his body started shaking. Brahmaa Jee said to Vishnu - "Bhagavan, Gayaasur is scared at the time of Poorn Aahuti, and his body is shaking." Vishnu called Dharm and asked him to keep the Dev Shilaa (Divine stone) on him and He asked all Devtaa to sit up on that stone. He asked them to keep His Gadaadhar (who bears Gadaa) idol also along with Devtaa. Hearing this Dharm kept that Dev Shilaa on Daitya's body."

Now what was this Dev Shilaa? - Dharm had a daughter from his wife Dharmvatee, her name was Dharmvrataa. She was a great ascetic. Brahmaa's son Mareech married her. As he was enjoying with her, that one day Maharshi got tired after bringing flowers and Kushaa from the forest. He took his food and asked his wife to massage his feet. Dharmvrataa started massaging Mareechi's feet. Muni slept. At that time Brahmaa Jee came there. Dharmvrataa thought, "What should I do? Should I continue with Muni's service or worship Brahmaa Jee? Brahmaa Jee is the Guru of Guru, he is the Guru of my husband also, so I should worship Brahmaa Jee." Thinking thus she rose and worshipped Brahmaa Jee.

In the meantime, Mareechi woke up and did not find his wife there. He got furious and cursed her - "You become a stone." Hearing this Dharmvrataa also got angry and said - "Hey Muni, I am innocent I left your service only to serve your father. You have cursed me in this situation, so you will also be cursed by Shiv Jee." Saying thus, that Pativrataa kept Muni's Shaap at one side and entered the fire. She performed severe penance for thousands of years. Pleased with her Vishnu etc Devtaa asked her to ask for any boon. She said - "Please, Free me from my curse."

Devtaa said - "Devee, Curse by Maharshi Mareechi cannot go waste, but from our footprints you will become a holy stone. You will have to assume the form of stone to stabilize Gayaasur's body. At that time you will be called by Devavrataa, Dev Shilaa, Sarv Dev Swaroopaa, Sarv Teerthmayee and Punya Shilaa names." Dharmvrataa said - "If you are so pleased with me, then I ask that after I become a stone, all Vishnu, Brahmaa and Rudra etc Devtaa and Lakshmee, Gauree etc Devee should always live on me." All Devta said, "So be it." and went away. So Dharm kept the same Devshilaa on Gayaasur's body. But still Gayaasur's body was shaking. Seeing this Rudra etc Devtaa sat on that stone, but his body was still shaking. Then Devtaa had to please Vishnu to help them. Vishnu gave them His Gadaadhar idol, they kept it on that stone, and thus Vishnu Himself had to be present on that body to stabilize his body.

When the idol of Aadi Gadaadhar was kept on it, Gaya got stabilized and Brahmaa Jee offered Poorn Aahuti. Later Gayaasur said to Devtaa - "Why did you play this game with me? Couldn't I be stabilized by Vishnu's words only? Since you have pressed me under a Shilaa (stone), you should bestow me a boon." Devtaa said - "O Daitya, We stabilized your body only to make a Teerth, that is why it will be a dwelling place for Vishnu, Brahmaa and Shiv. It will be more famous than all the Teerth, and this Teerth will give Brahm Lok to Pitar." After saying this all Devtaa started living there only. Other Devee and Teerth also started living there.

The same Bhagavaan is present in Gayaa in the form of Aadi Gadaadhar.

[Agni Puraan, 114]