Mbh 2.79.5a

Vaisampayana continued,--“And, O monarch, while king Dhritarashtra and the wise Vidura were thus talking with each other, there appeared in that assembly of the Kauravas and before the eyes of all, the best of the celestial Rishis. And appealing before them all, he uttered these terrible words, On the fourteenth year hence, the Kauravas, in consequence of Duryodhana’s fault, will all be destroyed by the might of Bhima and Arjuna’. And having said this, that best of celestial Rishis, adorned with surpassing Vedic grace, passing through the skies, disappeared from the scene. Then Duryodhana and Karna and Sakuni, the son of Suvala regarding Drona as their sole refuge, offered the kingdom to him. Drona then, addressing the envious and wrathful Duryodhana and Dussasana and Karna and all the Bharata, said, ‘The Brahamanas have said that the Pandavas being of celestial origin are incapable of being slain. The sons of Dhritarashtra, however, having, with all the kings, heartily and with reverence sought my protection, I shall look after them to the best of my power. Destiny is supreme, I cannot abandon them. The sons of Pandu, defeated at dice, are going into exile in pursuance of their promise. They will live in the woods for twelve years. Practising the Brahmacharyya mode of life for this period, they will return in anger and to our great grief take the amplest vengeance on their foes. I had formerly deprived Drupada of his kingdom in a friendly dispute. Robbed of his kingdom by me, O Bharata, the king performed a sacrifice for obtaining a son (that should slay me). Aided by the ascetic power of Yaja and Upayaja, Drupada obtained from the (sacrificial) fire a son named Dhrishtadyumna and a daughter, viz., the faultless Krishna, both risen from the sacrificial platform. That Dhrishtadyumna is the brother-in-law of the sons of Pandu by marriage, and dear unto them. It is for him, therefore that I have much fear.