In ancient times Shabbat was the reason for all the other days."" Analogously, this gracious and fine-tuned book might stand as the cornerstone of Drucker's splendid series. As one would expect, she evokes and explains the forms of observance from the lighting of two candles on Friday evening to the lighting of one, multiple candle at nightfall on Saturday--noting variations, and suggesting that any observance has meaning. She is aware that the prohibitions may seem like archaic formalities today; so she sets forth the ideas on which they are based. Why no carrying, outside of the house? ""The point of this law is that you do not try to change the world on Shabbat, even by simply moving an object from one place to another."" Another reason--the relief of unburdening yourself. But, Drucker points out most acutely: ""Every 'no' allows for a 'yes.' "" And she relates a legend that God gave the Jews Shabbat as a weekly foretaste of the perfect world. As usual, some simple recipes for traditional fare (hallah, cholent), and some simple instructions for appropriate crafts and games, are included. The quietly joyful reverence, and the interpretive specificity, especially suit the book to an ecumenical readership (somewhat older, perhaps, than the series norm).