Abraham Joshua Heschel, The Sabbath
To set apart one day a week for freedom, a day on which we would not use the instruments which have been so easily turned into weapons of destruction, a day for being with ourselves, a day of detachment from the vulgar, of independence of external obligations, a day on which we stop worshipping the idols of technical civilization, a day on which we use no money, a day of armistice in the economic struggle with our fellow men and the forces of nature—is there any institution that holds out a greater hope for man's progress than the Sabbath?
The solution of mankind's most vexing problem will not be found in renouncing technical civilization, but in attaining some degree of independence of it.
The Sambatyon is a legendary river mentioned as early as Pliny the Elder in the first century C.E. Pliny merely stated that there was “in Judea a river that runs dry every Sabbath.”
Josephus has a completely different account (Wars of the Jews): Recounting Titus’s departure from Judea in the aftermath of the Great Revolt, Josephus noted:
In the course of his march he saw a river, the nature of which deserves to be recorded in history. It runs between Arcea, located in Agrippa’s kingdom and Raphanea, and has an astonishing peculiarity. For, when it flows, it is a copious stream with a current far from sluggish; then all at once its sources fail and for the space of six days it presents the spectacle of a dry bed; again, as though no change had occurred, it pours forth on the seventh day just as before. And it has always been observed to keep strictly to this order; whence they have called it the Sabbatical river, so naming it after the sacred seventh day of the Jews.”
This is what Stoekl writes about this aggadah:
In several of the sources, it is stated or implied that the soul of Tyranus Rufus’s dead father cannot be raised on this day, leading the living son to fear that his father has in the underworld converted to Judaism. The father instead reveals that all those who do not observe the Sabbath of their own free will when alive are forced to do so when dead: during the week such souls undergo judgment and/or punishment, while only on the Sabbath are they left alone. This is an especially striking form of rabbinic revenge against the Romans, one which appears to address the typical Roman accusations discussed above: far from wasteful or otherwise negative, the Sabbath is revealed to be both pleasurable and of immense long-term benefit; no longer a particular Jewish oddity, it is here recast as, in at least some sense, a universal obligation. Most importantly, however, this example nicely parallels that of the Sambatyon in implying the Sabbath’s accord with the natural (under)world.
Agatharchadies (2nd century C.E.):
The people known as Jews ... have a custom of abstaining from work every seventh day; on those occasions they neither bear arms nor take any agricultural operations in hand, nor engage in any other form of public service, but pray with outstretched hands in the temples until the evening. Consequently, because the inhabitants, instead of protecting their city, persevered in their folly (anoian), Ptolemy, son of Lagus, was allowed to enter with his army; the country was thus given over to a cruel master, and the defect of a practice enjoined by law was exposed. That experience has taught the whole world, except that nation, the lesson not to resort to dreams and traditional fancies about the law, until the difficulties are such as to baffle human reason.
Ignatius, Epistle to the Magnesians
"Let us therefore no longer keep the Sabbath after the Jewish manner, and rejoice in days of idleness .... But let every one of you keep the Sabbath after a spiritual manner, rejoicing in meditation on the law, not in relaxation of the body, admiring the workmanship of God, and not eating things prepared the day before, nor using lukewarm drinks, and walking within a prescribed space, nor finding delight in dancing and plaudits which have no sense in them. And after the observance of the Sabbath, let every friend of Christ keep the Lord's [Day, Dominicam] as a festival, the resurrection-day, the queen and chief of all the days.