The Sabbath has been one of the most significant and beloved institutions of Jewish life since late antiquity. Over a period of several centuries, the classical Kabbalists developed a rich body of ritual and myth that articulated a fresh vision of the Sabbath. The mystical understanding of the Sabbath was assimilated by virtually every Jewish community. This volume is a translation and critical commentary to Sod ha-Shabbat, a treatise on the mystical Sabbath by the influential Spanish-Turkish Kabbalist, R. Meir ibn Gabbai. This important text, the most systematic treatment of the Sabbath in classical Kabbalah, has been inaccessible to the English reader until now. The study includes an Introduction to ibn Gabbai's life and work, accompanied by extensive critical notes that clarify general problems of translation and place the work in its historical context. Broader theoretical issues regarding myth and the ritual process are also discussed.