Read the following poem by edgar allen poe and answer the question that follows.
a dream within a dream take this kiss upon the brow!
and, in parting from you now,
thus much let me avow‚
you are not wrong, who deem
that my days have been a dream:
yet if hope has flown away
in a night, or in a day,
in a vision or in none,
is it therefore the less gone?
all that we see or seem
is but a dream within a dream.

i stand amid the roar
of a surf-tormented shore,
and i hold within my hand
grains of the golden sand‚
how few! yet how they creep
through my fingers to the deep
while i weep‚while i weep!
o god! can i not grasp
them with a tighter clasp?
o god! can i not save
one from the pitiless wave?
is all that we see or seem
but a dream within a dream?

what, if anything, does the sand in this poem symbolize? defend your answer in at least three complete sentences.