Mbh 5.190.1a

“‘Bhishma said, “Then all those ascetics (that dwell in Vatsabhumi), beholding the princess of Kasi firmly resolved on ascetic austerities, dissuaded her and enquired of her, saying, ‘What is thy business?’ Thus addressed, the maiden answered those ascetics, old in ascetic penances, saying, ‘Expelled I have been by Bhishma, prevented by him from the virtue that would have been mine by living with a husband! My observance of this vow is for his destruction and not for the sake of regions of bliss, ye that are endued with wealth of asceticism! Having compassed the death of Bhishma, peace will be mine. Even this is my resolve. He for whom mine hath been this state of continuous grief, he for whom I have been deprived of the region that would have been mine if I could obtain a husband, he for whom I have become neither woman nor man, without slaying in battle that son of Ganga I will not desist, ye that are endued with wealth of asceticism. Even this that I have said is the purpose that is in my heart. As a woman, I have no longer any desire. I am, however, resolved to obtain manhood, for I will be revenged upon Bhishma. I should not, therefore, be dissuaded by you.’ Unto them she said these words repeatedly. Soon, the divine lord of Uma, bearing the trident, showed himself in his own form unto that female ascetic in the midst of those great Rishis. Being asked to solicit the boon she wished, she begged of the deity my defeat. ‘Thou shalt slay him,’--were the words the god said unto that lady of great force of mind. Thus assured, the maiden, however, once more said unto Rudra, ‘How can it happen, O god, that being a woman I shall yet be able to achieve victory in battle. O lord of Uma, as a woman, my heart is quite stilled. Thou hast, however, promised me, O lord of creatures, the defeat of Bhishma.