The Prose Edda · Part 2
Gylfaginning 1
1.1King Gylfi ruled the land that men now call Sweden. It is told of him that he gave to a wandering woman, in return for her merry-making, a plow-land in his realm, as much as four oxen might turn up in a day and a night. But this woman was of the kin of the Æsir; she was named Gefjun. She took from the north, out of Jötunheim, four oxen which were the soils of a certain giant and, herself, and set them before the plow. And the plow cut so wide and so deep that it loosened up the land; and the oxen drew the land out into the sea and to the westward, and stopped in a certain sound. There Gefjun set the land, and gave it a name, calling it Selund. And from that time on, the spot whence the land had been torn up is water: it is now called the Lögr in Sweden; and bays lie in that lake even as the headlands in Selund. Thus says Bragi, the ancient skald: Gefjun drew from Gylfi gladly the wave-trove's freehold, Till from the running beasts sweat reeked, to Denmark's increase; The oxen bore, moreover, eight eyes, gleaming browlights, O'er the field's wide booty, and four heads in their plowing.