What signs did John receive to guide his journey to the east in "By the Waters of Babylon"?

In Stephen Vincent Benét's "By the Waters of Babylon," John (the protagonist) is going on a journey of discovery. This is the final step of his initiation as a priest for his tribe. When John feels he "is a man at last," he tells his father, who is also a priest, that he is ready to go on his journey. John's father worries about his son's very strong dreams about the Place of the Gods, in which John sees the gods walking. John's father cautions him that these dreams may "eat you up." For this reason, it really should not surprise readers that John ultimately feels he should go to the Place of the Gods for his journey, even if it is forbidden.

Once John begins his journey, he fasts and waits for a sign about where he ought to go. To end his fast, John manages to kill a panther by shooting an arrow through its eye. He also sees an eagle flying east. John reasons that if animals are traveling east, he can, too, even if it breaks his tribe's traditions.