Found at Aspiring Community:
 
        You Never Can Tell
                                              Ella Wilcox Wheeler

      YOU never can tell when you send a word,
      Like an arrow shot from a bow
      By an archer blind, be it cruel or kind,
      Just where it may chance to go.

      It may pierce the breast of your dearest friend.
      Tipped with its poison or balm,
      To a stranger's heart in life's great mart,
      It may carry its pain or its calm.

      You never can tell when you do an act
      Just what the result will be;
      But with every deed you are sowing a seed,
      Though the harvest you may not see.

      Each kindly act is an acorn dropped
      In God's productive soil
      You may not know, but the tree shall grow,
      With shelter for those who toil.

      You never can tell what your thoughts will do,
      In bringing you hate or love;
      For thoughts are things, and their airy wings
      Are swifter than carrier doves.

      They follow the law of the universe--
      Each thing must create its kind,
      And they speed o'er the track to bring you back
      Whatever went out from your mind.