What Turned Out to Be a Ray of Sunlight Through the Window

There is a patch of white
 as tall as I am, nearly,
   standing aslant on the wall.
    It is impossible to tell
     whether it is a swatch of new paint
      covering a wound in the original,
       or a vestige of underpaint,
        peeking out through a gap
         in a coat fourteen inches too short
          to hide it.
           Or perhaps a protected chink
            that took shelter behind family photos
             and thus escaped the stains and fades
              of years.
               Whatever it is, that patch is alone.
                So I watch the wall trying
                 to come to know itself.