Mahabharata Adi Parva Chapter 34:2

Mahabharata Adi Parva Chapter 34:2 Meanwhile, Sakra taking up the Amrita, wended back to heaven. The snakes after performing their ablutions, their daily devotions, and other sacred rites, returned in joy, desirous of drinking the Amrita. They saw that the bed of kusa grass whereon the Amrita had been placed was empty, the Amrita itself having been taken away by a counter-act of deception. And they began to lick with their tongues the kusa grass, as the Amrita had been placed thereon. And the tongues of the snakes by that act became divided in twain. And the kusa grass, too, from the contact with Amrita, became sacred thenceforth. Thus did the illustrious Garuda bring Amrita (from the heavens) for the snakes, and thus were the tongues of snakes divided by what Garuda did. "Then the bird of fair feathers, very much delighted, enjoyed himself in those woods accompanied by his mother. Of grand achievements, and deeply reverenced by all rangers of the skies, he gratified his mother by devouring the snakes. "That man who would listen to this story, or read it out to an assembly of good Brahmanas, must surely go to heaven, acquiring great merit from the recitation of (the feats of) Garuda.'" And so ends the thirty-fourth section in the Astika Parva of the Adi Parva.