In this excerpt from edgar allan poe's "the raven," what does the biblical reference to the healing “balm in gilead” signify? "prophet! " said i, "thing of evil! —prophet still, if bird or devil! — whether tempter sent, or whether tempest tossed thee here ashore, desolate, yet all undaunted, on this desert land enchanted— on this home by horror haunted—tell me truly, i implore— is there—is there balm in gilead? —tell me—tell me, i implore! " quoth the raven, "nevermore."