The casual reader of the siddur, the Jewish prayer book, does not exist—it’s not a book you’re likely to pick up at the airport, read halfway through, and then abandon because you’ve lost interest in the plot or sympathy with the leading character. Even if you wander into a strange synagogue for a bar mitzvah, your relationship to the siddur that comes to your hand is intensely practical and intimate as you find your way through it to the passage the people around you are reciting. It is a book with a public face and a private face, a sort of literary equivalent to Dr. Who’s Tardis, the time machine that looks small from the outside but contains infinite space within.