Where is the quote from To Kill a Mockingbird about the people in Maycomb knowing everything about everyone else?

From the text:

There was indeed a caste system in Maycomb, but to my mind it worked this way:
the older citizens, the present generation of people who had lived side by side for
years and years, were utterly predictable to one another: they took for granted
attitudes, character shadings, even gestures, as having been repeated in each
generation and refined by time. Thus the dicta No Crawford Minds His Own
Business, Every Third Merriweather Is Morbid, The Truth Is Not in the
Delafields, All the Bufords Walk Like That, were simply guides to daily living:
never take a check from a Delafield without a discreet call to the bank; Miss
Maudie Atkinson’s shoulder stoops because she was a Buford; if Mrs. Grace
Merriweather sips gin out of Lydia E. Pinkham bottles it’s nothing unusual—her
mother did the same.