The Sthalapurana of this sacred place is given in Brammanda Purana and Tampraparani Sthalapurana.
Once, God Perumal and Maha Laxmi Thayar were captivated by the beauty of this place and stayed on here. This annoyed the Bhoomi Devi, as at Her own place, she was not called to be with God. In a huff, she went to Pathala Loka. In her absence, the earth became dark and dry. The Devas saw this and pleaded to Perumal for restoration. Perumal went to Pathala Loka and brought back Bhoomi Devi. God Perumal gave his darshan here with Maha Laxmi Thayar and Bhoomi Devi. As He had saved the earth (Bhoomi) and the Bhoomi Devi, He is known as Bhoomi Palar here.
The importance of this place is outlined in another story also. Long ago, a Brahmin house holder, Yagna Sharma, who dis-respected Vasishta Putras, was cursed to become a demon. Redemption from such a curse was possible at Thiruppulingudi only. At the same time, Lord Indra who committed a Brammahatty Dosha approached his Guru, Bruhaspathi, for advice. Guru Bruhaspathi brought Lord Indra to Thiruppulingudi. Lord Indra prayed to Bhoomi Palar and took bath at the tank here (hence the name, Indra Theertham). Lord Indra was relieved of his Dosham and in thankfulness, he performed a yaga. Yagna Sharma (then in the form of a demon) was also at this spot. God Perumal appeared at the Yaga Kundam and using His Gatha, He hit the demon and gave him redemption from the Curse.