What book could you read over and over again?

Some books I have read do thrill me from cover to cover, but they are mostly fantasy and fiction.  I do not see myself returning to read them.  I can only picture myself returning portions of certain books to see what other deep mysteries of life or what mix of emotions I may discover. I owe you a book, by name, since I am responding to the prompt.   Esther, Jewish story, explaining the Feast of Purim and a whole lot more.