Dvalin is the name of a dwarf in Völuspá, str. 11, 14; Hávamál, str. 143, and in other of the Edda poems. It is, in fact, the typical name for a dwarf. Cf. also Gylfaginning, ch. 14, and Skáldskaparmál, ch. 3, 57. Dulin does not occur elsewhere, though Durin is found in Völuspá, str. 10.
Standing in the doorway of the stone, etc. Cf. Völuspá, str. 48.
Your sword, etc. Cf. Skáldskaparmál, ch. 49. "Now I have drawn Dáinsleif, which the dwarfs made and which must cause a man's death every time it is drawn, and never fails in its stroke."
Tyrfing. It has been suggested that this name is derived from tyrfi, 'resinous fir-tree,' owing to its flaming like resinous fir-wood. In early times it was customary for swords to be called by names ending in -ing. Cf. the swords Hrunting in Beowulf, l. 1457, etc., Nagling, ibid., l. 2680, and Mimming in Waldhere, l. 3, etc., etc.
Perms. The text has um Bjarmaland 'in the land of the Bjarmar,' i.e. the Beormas of Ohthere's Voyage in Alfred's translation of Orosius. It is generally reached, not as here, apparently, by the Baltic, but by voyages round the North Cape. The name is generally supposed to be connected with Perm, and in early times may have comprehended the Zyrianians, as well as the Permians proper and the Votiaks. There is some evidence from place-names that this group of languages was once spoken as far west as the White Sea. Cf. Abercromby, The Pre- and Proto-historic Finns, p. 10 f.
Svafrlami. The text (H) followed by the Reykjavik edition here has Sigrlami—which can hardly be right. Rafn's ed. reads Svafrlami.
Twelve sons. For Arngrim's Sons, Cf. Hyndluljóth, str. 23, 24; Saxo Grammaticus, Dan. Hist., pp. 203-205; Saga of Örvar Odd, ch. 14.
Twins. See the Saga of Harold the Fairhaired (Heimskringla), ch. 18, where again we find twins both receiving the same name.
Mistletoe. A sword of the same name occurs in the Saga of Hromund Greipsson (see above).