“ Suffering passes, while love is eternal. That’s a gift that you have received from God” What does this quote mean??

Which line in this excerpt from "the love song of j. alfred prufrock" by t.s. eliot uses synecdoche? shall i say, i have gone at dusk through narrow streets and watched the smoke that rises from the pipes of lonely men in shirt-sleeves, leaning out of windows? i should have been a pair of ragged claws scuttling across the floors of silent seas.