what is the main idea in the third stanza of the poem she walks in beauty like a night

Third paragraph of the poem:

"And on that cheek, and o’er that brow,

So soft, so calm, yet eloquent,

The smiles that win, the tints that glow,

But tell of days in goodness spent,

A mind at peace with all below,

A heart whose love is innocent!"

According to the scholars, Byron wrote this poem after he met his cousin at a funeral. The entirety of the poem talks about a woman unaware that her presence becomes a symbol of beauty to someone witnessing her presence. Paragraph 3 of this poem describes a quiet, magnificent, finesse (well refined) woman. Her smile alone and when she blushes is very expressive, meaningful and revealing. Her radiance is the ultimate expression of a peaceful beauty because she spent her days doing good deeds and she is a good person with a clear conscience. She may or may not be in love with someone, but it is pure and definitely not the sexual kind of love.