Srimad Bhagvata Mahapurana: Book 8: Chapter 6: Verses 25-39
Transportation of Mount Mandara (to serve as a churn-staff for stirring the ocean of milk)
You should not be afraid of the poison, called Kalakuta, that will come out of the ocean (of milk). Nor should you ever evince covetousness or greed with respect to the objects (that may be churned out of the ocean) nor give vent to anger (if they are coveted or even taken by force by the demons) Sri Suka continued : Having thus duly instructed the gods, the almighty Lord Sri Hari (the supreme Person), whose movements are (altogether) guided by His own free will, vanished out of their sight, O Pariksit ! Bowing to the Lord, Brahma (the father of the lords of creation) as well as Lord Siva (the Source of the universe) then returned each to His own. realm, while the gods (headed by Indra) called on Bali. King Bali (the ruler of the Daityas), who was praiseworthy (in everyway) and knew when to wage war and when to come to terms (with the enemy), kept under restraint his own generals, who got excited at the (very) sight of the enemy (the gods), even though the latter were not (at all) prepared for action. The gods (now) approached Bali (son of Virocana), who sat (on his throne) guarded by leaders of Asura troops and, having conquered all (the three worlds), was invested with the highest (royal) splendour. Having conciliated Bali with his polished language, the highly talented Indra told him all that he had received instruction in from Lord Visnu (the supreme Person).
The proposal found favour with the Daitya king (Bali) as well as with whosoever were present there, viz., Sambara, Aristanemi and other demon chiefs and denizens of Tripura. Having arrived at a (mutual) understanding, the gods and the Asuras (demons), who had (now) cultivated friendship, thereupon put forth their best energies for (obtaining) nectar, O chastiser of foes ! Then, uprooting Mount Mandara by their might and roaring (like lions), the arrogant gods and demons, who were (all) full of energy and whose arms were strong as bludgeons, proceeded to take it to the seashore. Exhausted by carrying their load to a long distance and unable to carry it (any) further, Indra, Bali (son of Virocana)and others helplessly dropped it on the way. While falling down, that mountain, which resembled Mount Sumeru (the mountain of gold), crushed under its huge weight numerous gods and demons on that spot.
Finding them disheartened and with their arms, thighs and necks broken, the Lord appeared there on the back of Garuda (the king of birds). Perceiving the gods and demons badly squeezed by the falling down of the mountain, He revived the gods by His (mere) look as though they were (quite) unhurt. Nay, placing the mountain on (the back of) Garuda with one hand by way of sport and mounting the bird (Himself), He flew to the seashore, surrounded by the gods and demons. Taking down the mountain from his shoulder and placing it on the seaside, the celebrated Garuda (possessed of beautiful wings), the foremost of winged creatures, withdrew, when discharged by Sri Hari (so as to make room for Vasuki, the king of serpents, who was too much afraid of Garuda, his mortal enemy, to arrive in the latter's presence).
Thus ends the sixth discourse, entitled "The transportation of Mount Mandara", comprised in the story of the churning of the ocean for nectar, in Book Eight of the great and glorious Bhagavata-Purana, otherwise known as the Paramahamsa-Samhita.