The origin and development of the Old Testament Sabbath

Since post-exilic times both the OT and Judaism have ascribed to the observance of the Sabbath as a weekly day of rest great importance. In pre-exilic times abstinece from work on the seventh day was not related to the Sabbath, which was a monthly lunar festival analogous to the Babylonian sap/battu. The Exile paved the way for the post-exilic identification of both institutions. The full-moon day became part of the celebration of Yahweh's kingship in Jerusalem and hence Yahweh's special day, a symbol of his universal sovereignty, of the unity and equality of mankind, and of the negation of other gods. The Sabbath now becomes a distinctive feature of Judaism.