It depends on how you interpret it. While reading it, I interpret it as he means to say that love is as innocent as a person can make it. When he states she walks in beauty, he is most likely referring to the idea that she is beautiful and has a innocent lifestyle. My apologies if this is not the answer you are looking for.
Answer:
See explanation.
Explanation:
Text based evidence is factual and it for sure a reliable source. Opinions are often biased and not reliable to use as proof.