Note 983 — Chapter XIII · THE SWORD AMONGST THE BARBARIANS (EARLY ROMAN EMPIRE).
Reading edition
So we find the god Tyr or Tuisco (regent of Tuesday), the Monthu or Mars of the North, figured in the Runes as a barbed spear ᛏ (resembling the planetary emblem of Mars). He afterwards became the Sword-god. From the Tyr-rune is derived ᛠ Er (= hêru, the sword), or Aer, which resembles the Greek ἄορ, and which Jacob Grimm connects with Ἄρης, æs and Eisen (Jähns, p. 14).