 The poem continues in verse, where Sigrdrífa provides Sigurd with knowledge in inscribing runes, mystic wisdom, and prophecy.In the "Prose Edda", written in the 13th century by Snorri Sturluson, valkyries are first mentioned in chapter 36 of the book "Gylfaginning", where the enthroned figure of High informs Gangleri (King Gylfi in disguise) of the activities of the valkyries and mentions a few goddesses.High says "there are still others whose duty it is to serve in Valhalla.