The Great Epic of the Bhārata dynasty 1.35.4

1.35.4

tatra netramabhūnnāgo vāsukirbalināṃ varaḥ |
samāpyaiva ca tatkarma pitāmahamupāgaman || 4 ||

"And much time did not elapse from this, when the gods and the Asuras, assembling together, churned the abode of Varuna. And Vasuki, the foremost of all gifted with strength, became the churning-cord. And directly the work was over, the king of the snakes presented himself before the Grandsire. And the gods, accompanied by Vasuki, addressed the Grandsire, saying, 'O lord, Vasuki is suffering great affliction from fear of (his mother's curse). It behoveth thee to root out the sorrow, begotten of the curse of his mother, that hath pierced the heart of Vasuki desirous of the weal of his race. The king of the snakes is ever our friend and benefactor. O Lord of the gods, be gracious unto him and assuage his mind's fever.'