describe bob ewell's meeting with Atticus by the post office and state Atticus response

Mr. Ewell saw Atticus by the post office, spat in his face, and told him that, "he'd get him if it took the rest of his life." Atticus is unconcerned about Mr. Ewell's threat, and tells his worried children that Mr. Ewell, who has been publicly discredited by the trial, just needs to feel like he is retaliating against someone, and better it be Atticus than the Ewell children.