Answer:
In the poem “ A Valentine” by Edgar Allan Poe (if this is actually the poem) the elements from the poem to which words treasure, talisman, and three eloquent words refer are the Valentine's name.
This poem represents a riddle:
"(...)Search narrowly the lines! -- they hold a treasure
Divine -- a talisman -- an amulet
That must be worn at heart." (Hint of the Valentine)
And the answer is the Valentine’s name:
"For her this rhyme is penned, whose luminous eyes, (This could mean that, as she is the purpose of the poem, she is the riddle)
Brightly expressive as the twins of Leda,
Shall find her own sweet name, that, nestling lies
Upon the page, enwrapped from every reader.
" (Here he gives us the answer: If the riddle is her name; we shall find it upon the page"
"(...) You will not read the riddle, though you do the best you can do."
Her name is the riddle, that's why we wont find in and we won't be able to read it.
