Was the Sabbath once a full-moon day? Babylonian tablets hint so
An Akkadian word, shapattu, named the day of the full moon, and a list from Ashurbanipal's library glosses it as the day the gods' hearts rest. Some scholars see the roots of the weekly Sabbath there. Others doubt the words are even related. The evidence cuts both ways.
In Judaism, Christianity and Islam, a weekly day is set apart for rest and worship: Saturday for Jews, Sunday for Christians, Friday for Muslims. The Hebrew Shabbat first appears in the Genesis creation story, where God stops work on the seventh day and blesses it. Keeping it is among the Ten Commandments, counted fourth in Judaism, Eastern Orthodoxy and most Protestant churches but third among Catholics and Lutherans. Even the commandment's wording differs: the Masoretic text says remember the day, the Samaritan Pentateuch says keep it.
Origins are debated. Besides the full-moon link, some point to an Assyrian religious calendar that labelled the 7th, 14th, 19th, 21st and 28th days of a lunar month as holy, or evil, meaning unsuitable days. On them the king avoided chariot riding and meat, officials faced restrictions, ordinary people could not make a wish, and the 28th was known as a rest day. Critics reply that these days were not reliably a week apart and did not halt work generally. Still, some studies find that the biblical Sabbath sometimes carried a monthly rather than weekly sense.
Outside the Bible, the earliest possible mention sits on a 7th-century BCE potsherd from the fortress of Mesad Hashavyahu, describing a worker's tasks before shbt, though that may just mean stopping work.
In the Hebrew Bible, the day ran from sundown on the sixth day to sundown on the seventh. Isaiah treats it as a joy, and 2 Kings shows people visiting prophets on it. Community-wide worship was not originally required: priests offered sacrifices at holy sites while families rested at home. Exodus lists violation as grounds for expulsion or even death. Most observant Jews regard it as a covenant sign recalling both Creation and the Exodus, while most Sabbath-keeping Christians hold that the whole world has been bound to the seventh day since Creation.
Source: Sabbath
