The Prose Edda · Part 3
Skáldskaparmál 8
8.1"How should one periphrase Heimdallr? By calling him Son of Nine Mothers, or Watchman of the Gods, as already has been written; or White God, Foe of Loki, Seeker of Freyja's Necklace. A sword is called Heimdallr's Head: for it is said that he was pierced by a man's head. The tale thereof is told in Heimdalar-galdr; and ever since a head is called Heimdallr's Measure; a sword is called Man's Measure. Heimdallr is the Possessor of Gulltoppr; he is also Frequenter of Vágasker and Singasteinn, where he contended with Loki for the Necklace Brísinga-men, he is also called Vindlér. Úlfr Uggason composed a long passage in the Húsdrápa on that legend, and there it is written that they were in the form of seals. Heimdallr also is son of Odin.