Bulgakov is making a bold assertion about literature here. The master's book is so powerful that not only can it not be destroyed, but its characters come to life as well. When the master wrote of Pilate, he effectively changed the past, and his characters became as eternal as the story. Matthew the Levite reappears on p. 405. The study of this past-present link is complicated by the fact that time and space are always somewhat ambiguous and imprecise in Woland's presence.
Hours fly by in a matter of seconds, and a few days seem to take no time at all.
A small Moscow flat becomes a boundless palace. The master does have this power, though. No matter how tenuous the links between past and present may be, it is clear that by the end of The Master and Margarita they have become as one. At the deepest level, The Master and Margarita is not only a book that contains another book, but also a book about books, writing, and authors. In Pushkin's Eugene Onegin the narrator was the writer of the book itself.