Mahabharata 1.49.16

1.49.16

amoghaṃ naḥ kṛtaṃ tatsyādyadahaṃ tava dhīmate |
pitre dattā vimokṣārthaṃ kathaṃ vā putra manyase || 16 ||

"Vasuki, the best of snakes, hearing those words, bestowed me, O thou of godlike looks, on thy high-souled father some time before the commencement of the sacrifice. And from that marriage thou art born of me. That time has come. It behoveth thee to protect us from this danger. It behoveth thee to protect my brother and myself from the fire, so that the object, viz., our relief, for which I was bestowed on thy wise father, may not be unfulfilled. What dost thou think, O son?'