S habbat is a precious oasis after six fast-moving, multitasking days. Leading Friday-night services as the senior rabbi at Central Synagogue in Manhattan never feels like work; it fills me with a buoyant Sabbath spirit. The rest of my Shabbat includes lively meals with friends and family that linger until sundown. Shabbat is a sacred luxury; it releases me from errands, email, and exercise, and gives me the freedom of knowing that there is nothing else I should be doing beyond communing with