Answer:
Precious but mysterious
Step-by-step explanation:
A Valentine is a lyrical poem written by Edgar Allan Poe. However, this is not just a poem. It's also a riddle that Poe made to reveal his secret lover. He is expressing his love for a woman, to whom he can't confess directly because she’s already married.
Based on the given words, we can conclude that, to the poet, love is precious but mysterious. It's precious like a treasure but mysterious like a riddle.