William Shakespeare's "Sonnet 130" contradicts most poetry which speaks to the beauty of a woman. According to the speaker, his lover is incomparable to anything in nature. Nature is far more beautiful than the lover.
The final two lines, or the ending couplet, continues to support what the speaker has claimed to this point. Although the lover is nothing like the natural phenomenons found in the world, she proves to be just as "rare." The speaker states his understanding that a women is not comparable to nature, for it is far too phenomenal. Illuminating this, the speaker also states that he understands that while other poets may tend to exaggerate the beauty of other women, women prove to be just as rare a beauty as the elements of nature. In essence, neither can be compared to the other. Each possess its (or her) own beautiful qualities.