Cite two lines that reveal that a sense of mystery about the wall is broken in the poem, Mending Wall.

It seems as if nature is attempting to destroy the barriers that man has created on the land, even as man continues to repair the barriers, simply out of habit and tradition. The speaker suggests magical Elves are the culprit but this mystery is broken by his neighbor Bringing a stone grasped firmly by the top In each hand, like an old-stone savage armed.