Analysis of The Moon, how definite its orb! (fragment)

The Moon, how definite its orb!
   Yet gaze again, and with a steady gaze--
   'Tis there indeed,--but where is it not?--
   It is suffused o'er all the sapphire Heaven,
   Trees, herbage, snake-like stream, unwrinkled Lake,
   Whose very murmur does of it partake
   And low and close the broad smooth mountain
   Is more a thing of Heaven than when
   Distinct by one dim shade and yet undivided from the universal cloud
  In which it towers, finite in height.