She Walks in Beauty Principles Quotes

The sound of this line, with its repeated s sound (a.k.a. "sibilance"), reflects the meaning of the line as well: the line sounds as soothing and "serene" as her thoughts supposedly are.

The speaker assumes that the calm and "serene" expression on the woman's face reflects the "pur[ity]" of her mind.

The speaker also assumes that the woman's sweet expression "tell[s]" the story of her past goodness – that's a lot to read just from someone's facial expression.

The calmness of her face makes the speaker assume that she's "at peace" with everyone. There's nothing to make her anxious or worried.

In the final line of the poem, the speaker reassures us (in case we were suspicious) that the woman is "innocent." She's not going to allow him to seduce her, or do anything else of that nature, so stop thinking that.