Mbh 12.363.1

"'"'Surya said, "This Being is not the god of fire, he is not an Asura. Nor is he a Naga. He is a Brahmana who has attained to heaven in consequence of his having been crowned with success in the observance of the vow called Unccha.[1941] This person had subsisted upon fruits and roots and upon the fallen leaves of trees. He had sometimes subsisted upon water, and sometimes upon air alone, passing his days with concentrated soul. The deity Mahadeva had been gratified by him with constant recitation of the Samhitas. He had endeavoured to accomplish those acts that lead to heaven. Through the merits of those acts he hath now attained to heaven. Without wealth and without desire of any kind, he had observed the vow called Unccha in the matter of his sustenance. This learned Brahmana, ye Nagas, had been devoted to the good of all creatures. Neither deities, nor Gandharvas, nor Asuras, nor Nagas, can be regarded as superior to those creatures that attain to this excellent end of coming into the solar disc?"--Even such, O regenerate one, was the wonderful incident that I beheld on that occasion. That Brahmana, who was crowned with success by the observance of the Unccha vow and who thus obtained an end that persons crowned with ascetic success acquire, to this day, O regenerate one, goes round the Earth, staying in the disc of Surya!'"'"