Shiva Purana
महेन्द्रमुख्या गीर्वाणा नागाः पातालवासिनः ॥ रत्नान्यादाय बहुशस्ससरित्का महाब्धयः ॥ २२॥
Mahendra and other gods, the Nāgas residing in the nether regions came there. Taking gems with them many great oceans and rivers came there.
english translation
mahendramukhyA gIrvANA nAgAH pAtAlavAsinaH ॥ ratnAnyAdAya bahuzassasaritkA mahAbdhayaH ॥ 22॥
hk transliteration by Sanscript