Old English sabat "Saturday as a day of rest," as observed by the Jews, from Latin sabbatum, from Greek sabbaton, from Hebrew shabbath, properly "day of rest," from shabath "he rested." Spelling with -th attested from late 14c., not widespread until 16c.
The Babylonians regarded seventh days as unlucky, and avoided certain activities then; the Jewish observance might have begun as a similar custom. Among European Christians, from the seventh day of the week it began to be applied early 15c. to the first day (Sunday), "though no definite law, either divine or ecclesiastical, directed the change" [Century Dictionary], but elaborate justifications have been made. The change was driven by Christians' celebration of the Lord's resurrection on the first day of the week, a change completed during the Reformation.
The original meaning is preserved in Spanish Sabado, Italian Sabbato, and other languages' names for "Saturday." Hungarian szombat, Rumanian simbata, French samedi, German Samstag "Saturday" are from Vulgar Latin sambatum, from Greek *sambaton, a vulgar nasalized variant of sabbaton. Sabbath-breaking attested from 1650s.
The holy day of rest and reflection observed each Saturday among the Jews. This custom fulfills the third of the Ten Commandments (“Remember the Sabbath day, to keep it holy”). The Sabbath commemorates the last of the seven days of Creation as described in the Book of Genesis, the day God rested from his labors of creating the heavens and the Earth.
Note: Christians have traditionally kept Sunday as a weekly day of rest in adaptation of the Jewish observance, and in commemoration of the Resurrection of Jesus. Some denominations, such as the Seventh-Day Adventists, observe Saturday as the Sabbath.
(Heb. verb shabbath, meaning "to rest from labour"), the day of rest. It is first mentioned as having been instituted in Paradise, when man was in innocence (Gen. 2:2). "The sabbath was made for man," as a day of rest and refreshment for the body and of blessing to the soul. It is next referred to in connection with the gift of manna to the children of Israel in the wilderness (Ex. 16:23); and afterwards, when the law was given from Sinai (20:11), the people were solemnly charged to "remember the sabbath day, to keep it holy." Thus it is spoken of as an institution already existing. In the Mosaic law strict regulations were laid down regarding its observance (Ex. 35:2, 3; Lev. 23:3; 26:34). These were peculiar to that dispensation. In the subsequent history of the Jews frequent references are made to the sanctity of the Sabbath (Isa. 56:2, 4, 6, 7; 58:13, 14; Jer. 17:20-22; Neh. 13:19). In later times they perverted the Sabbath by their traditions. Our Lord rescued it from their perversions, and recalled to them its true nature and intent (Matt. 12:10-13; Mark 2:27; Luke 13:10-17). The Sabbath, originally instituted for man at his creation, is of permanent and universal obligation. The physical necessities of man require a Sabbath of rest. He is so constituted that his bodily welfare needs at least one day in seven for rest from ordinary labour. Experience also proves that the moral and spiritual necessities of men also demand a Sabbath of rest. "I am more and more sure by experience that the reason for the observance of the Sabbath lies deep in the everlasting necessities of human nature, and that as long as man is man the blessedness of keeping it, not as a day of rest only, but as a day of spiritual rest, will never be annulled. I certainly do feel by experience the eternal obligation, because of the eternal necessity, of the Sabbath. The soul withers without it. It thrives in proportion to its observance. The Sabbath was made for man. God made it for men in a certain spiritual state because they needed it. The need, therefore, is deeply hidden in human nature. He who can dispense with it must be holy and spiritual indeed. And he who, still unholy and unspiritual, would yet dispense with it is a man that would fain be wiser than his Maker" (F. W. Robertson). The ancient Babylonian calendar, as seen from recently recovered inscriptions on the bricks among the ruins of the royal palace, was based on the division of time into weeks of seven days. The Sabbath is in these inscriptions designated Sabattu, and defined as "a day of rest for the heart" and "a day of completion of labour." The change of the day. Originally at creation the seventh day of the week was set apart and consecrated as the Sabbath. The first day of the week is now observed as the Sabbath. Has God authorized this change? There is an obvious distinction between the Sabbath as an institution and the particular day set apart for its observance. The question, therefore, as to the change of the day in no way affects the perpetual obligation of the Sabbath as an institution. Change of the day or no change, the Sabbath remains as a sacred institution the same. It cannot be abrogated. If any change of the day has been made, it must have been by Christ or by his authority. Christ has a right to make such a change (Mark 2:23-28). As Creator, Christ was the original Lord of the Sabbath (John 1:3; Heb. 1:10). It was originally a memorial of creation. A work vastly greater than that of creation has now been accomplished by him, the work of redemption. We would naturally expect just such a change as would make the Sabbath a memorial of that greater work. True, we can give no text authorizing the change in so many words. We have no express law declaring the change. But there are evidences of another kind. We know for a fact that the first day of the week has been observed from apostolic times, and the necessary conclusion is, that it was observed by the apostles and their immediate disciples. This, we may be sure, they never would have done without the permission or the authority of their Lord. After his resurrection, which took place on the first day of the week (Matt. 28:1; Mark 16:2; Luke 24:1; John 20:1), we never find Christ meeting with his disciples on the seventh day. But he specially honoured the first day by manifesting himself to them on four separate occasions (Matt. 28:9; Luke 24:34, 18-33; John 20:19-23). Again, on the next first day of the week, Jesus appeared to his disciples (John 20:26). Some have calculated that Christ's ascension took place on the first day of the week. And there can be no doubt that the descent of the Holy Ghost at Pentecost was on that day (Acts 2:1). Thus Christ appears as instituting a new day to be observed by his people as the Sabbath, a day to be henceforth known amongst them as the "Lord's day." The observance of this "Lord's day" as the Sabbath was the general custom of the primitive churches, and must have had apostolic sanction (comp. Acts 20:3-7; 1 Cor. 16:1, 2) and authority, and so the sanction and authority of Jesus Christ. The words "at her sabbaths" (Lam. 1:7, A.V.) ought probably to be, as in the Revised Version, "at her desolations."