Mbh 12.324.2b

Thither all the regenerate Rishis and royal sages and the Regents of the world and the Sadhyas along with the Vasus, and the Adityas, the Rudras, and Surya and Chandramas, and the Maruts, and the Oceans, and the Rivers and the Aswins, the Deities, the Gandharvas, and Narada and Parvata and the Gandharva Viswavasu, and the Siddhas, and the Apsaras. There Mahadeva, called also by the name of Rudra, sat, decked with an excellent garland of Karnikara flowers, and blazed with effulgence like the Moon with his rays. In those delightful and celestial woods populous with deities and heavenly Rishis, the great Rishi remained, engaged in high Yoga-contemplation, from desire of obtaining a son. His strength suffered no diminution, nor did he feel any pain. At this the three worlds were much amazed. While the Rishi, possessed of immeasurable energy, sat in Yoga, his matted locks, in consequence of his energy, were seen to blaze like flames of fire. The illustrious Markandeya it was from whom I heard of this. He used always to recite to me the acts of the deities. It is for this that the matted locks of the high-souled and (Island-born) Krishna, thus emblazed by his energy on that occasion, seem to this day to be endued with the complexion of fire. Gratified with such penances and such devotion, O Bharata, of the Rishi, the great God resolved (to grant him his wish). The Three-eyed deity, smiling with pleasure, addressed him and said,--O Island-born one, thou shalt get a son like to what thou wishest! Possessed of greatness, he shall be as pure as Fire, as Wind, as Earth, as Water, and as Space! He shall be possessed of the consciousness of his being Brahma's self; his understanding and soul shall be devoted to Brahma, and he shall completely depend upon Brahma so as to be identifiable with it!"'"