In what chapter of Harper Lee's To Kill a Mockingbird did Calpurnia say the following passage: Folks don’t like to have somebody around...

Calpurnia says the passage in question in Chapter 12 of Harper Lee's To Kill a Mockingbird, while walking back to the Finches' home after having brought Scout and Jem to her church as her guests.

In Chapter 12, Atticus has left town to attend an "emergency session" of the state legislature, leaving Scout and Jem to Calpurnia's care. Calpurnia is concerned that Atticus didn't have time to find out in advance if Scout and Jem's Sunday school teacher will be at church on Sunday, and if Scout and Jem go by themselves unsupervised, they could cause trouble. Therefore, she invites them to attend the all-black church service with her as her guests. Attending church with Calpurnia proves to be a real eye-opener for the children as they learn things about Calpurnia they never realized before. Scout's new knowledge of Calpurnia particularly helps her develop a new-found respect for Calpurnia.

One thing the children learn about Calpurnia they never knew before is that she speaks differently when she is with the Finches as opposed to when she is among the African Americans of Maycomb. Towards the end of Chapter 12, Jem is the first to note that Calpurnia speaks very grammatically, unlike the rest of the African Americans in Maycomb. However, he further notes that in church, while speaking with other African Americans, Calpurnia did use the same dialect as her fellow African Americans. When both Jem and Scout want to know why Calpurnia does this when she "know[s] it's not right," Calpurnia gives the speech in question in reply.

In saying the above, Calpurnia is explaining that it is boastful to always "tell all you know," which shows us the great sense of humility she has. She further explains that it is pointless for her to speak grammatically because it won't change the behavior of other African Americans. As Calpurnia explains, they have to "want to learn themselves," and if they don't want to learn, then there is nothing anyone can do to change their minds. All that can be done is to continue to act with respect and humility by "talk[ing] their language" (Ch. 12).

In addition to giving a lesson in respect and humility, Calpurnia's speech underscores the theme of disparity found throughout the book. Author Lee demonstrates that inequalities are a direct result of  disparities in education, and inequality will never fully be resolved until the education gap is fully bridged.