SB 8.7.1

śrī-śuka uvāca
te nāga-rājam āmantrya
 phala-bhāgena vāsukim
parivīya girau tasmin
 netram abdhiṁ mudānvitāḥ
ārebhire surā yattā
 amṛtārthe kurūdvaha
Synonyms: 
śrī-śukaḥ uvāca — Śrī Śukadeva Gosvāmī said; te — all of them (the demigods and the demons); nāga-rājam — the king of the Nāgas, snakes; āmantrya — inviting, or requesting; phala-bhāgena — by promising a share of the nectar; vāsukim — the snake Vāsuki; parivīya — encircling; girau — Mandara Mountain; tasmin — unto it; netram — the churning rope; abdhim — the Ocean of Milk; mudā anvitāḥ — all surcharged with great pleasure; ārebhire — began to act; surāḥ — the demigods; yattāḥ — with great endeavor; amṛta-arthe — for gaining nectar; kuru-udvaha — O King Parīkṣit, best of the Kurus.
Translation: 
Śukadeva Gosvāmī said: O best of the Kurus, Mahārāja Parīkṣit, the demigods and demons summoned Vāsuki, king of the serpents, requesting him to come and promising to give him a share of the nectar. They coiled Vāsuki around Mandara Mountain as a churning rope, and with great pleasure they endeavored to produce nectar by churning the Ocean of Milk.