The Arrow and the Song

I shot an arrow into the air, It fell to earth, I knew not where; For, so swiftly it flew, the sight Could not follow it in its flight. I breathed a song into the air, It fell to earth, I knew not where; For who has sight so keen and strong, That it can follow the flight of song? Long, long afterward, in an oak I found the arrow, still unbroke; And the song, from beginning to end, I found again in the heart of a friend.