Mbh 13.125.8a

"'"Sakra said, 'Thinking in one's mind of Kurukshetra and Gaya and Ganga and Prabhasa and the lakes of Pushkara, one should dip one's head in water. By so doing one becomes cleansed of all one's sins like Chandramas freed from Rahu. One should bathe in this way for three days in succession and then fast for every day. Besides this, one should touch (after bathing) the back of a cow and bow one's head to her tail.' Vidyutprabha, after this, once more addressing Vasava, said, 'I shall declare a rite that is more subtle. Listen to me, O thou of a hundred sacrifices. Rubbed with the astringent powder of the hanging roots of the banian and anointed with the oil of Priyangu, one should eat the Shashtika paddy mixed with milk. By so doing one becomes cleansed of all one's sins[543]. Listen now to another mystery unknown to many but which was discovered by the Rishis with the aid of meditation. I heard it from Vrihaspati while he recited it in the presence of Mahadeva. O chief of the deities, do thou hear it with Rudra in thy company, O lord of Sachi! If a person, ascending a mountain, stands there on one foot, with arms upraised and joined together, and abstaining from food looks at a blazing fire, he acquires the merits of severe penances and obtains the rewards that attach to fasts. Heated by the rays of the sun, he becomes cleansed of all his sins. One who acts in this way in both the summer and the winter seasons, becomes freed from every sin. Cleansed of every sin, one acquires a splendour of complexion for all time. Such a man blazes with energy like the Sun or shines in beauty like the Moon!' After this, the chief of the deities, viz.