From a reader:

Jonah,
DC had to have come up with the spear idea by ripping off Richard Wagner, who used that very same spear in his opera “Parsifal,” which in turn was based on the German legend “Parzifal.” In it, the spear (along with the Holy Grail) is the source of great powers of good; the heroic Knights of the Grail suffer greatly when the spear is stolen; their king (who has a permanent wound in his side) is healed by the spear after Parsifal regains it from the enemy. I had no idea DC was so classically minded!