The Younger Edda — Snorri Sturluson

King Gylfe ruled the lands that are now called Svithjod (Sweden). Of him it is said that he gave to a wayfaring woman as a reward for the entertainment she had afforded him by her story-telling a plow-land in his realm as large as four oxen could plow it in a day and a night But this woman was of the asa-race; her name was Gefjun.' (Excerpt from Chapter 1)