Answer:
Bob was mad at Finch for defending a black man. So when he saw Finch at the post office, he cursed at him, spit in his face, and threaten to kill him. Finch responded by taking out his handkerchief and wiped his face, stood there and took all of Bob's cursing at him. What made Bob angry was the face that Finch stood there calmed and didn't react to Bob in a why that most would have done; i.e. got into an argument or physical altercation with him in the street. When Bob responded to Finch's non-physical action, he asked Finch, "Too proud to fight, you n-loving *b*?", and Finch responded in a polite manner of "No, too old," and walked away.
.you should know what the "n" means because I could not type it due to the racial content that is not approved by this site.
and the *b* means b-a--s--t-a--r-d
