The last chapter of Tractate Shabbat begins with a mishnah about being caught on the road as Shabbat arrives:
One who was traveling on Shabbat eve and night fell, and Shabbat began while he was still en route, gives his money pouch to a gentile traveling with him. And if there is no gentile with him he places it on the donkey.
As we’ve been reminded countless times already in this tractate, carrying objects in the public domain on Shabbat is forbidden. But the solution proposed in this mishnah is odd, because we know that it’s also forbidden to have a non-Jew perform actions on one’s behalf during Shabbat that one is not allowed to do oneself. So why the leniency here?
The Gemara explains:
The Sages maintain that a person does not restrain himself when faced with losing his money. If you do not permit him to give his pouch to a gentile, he will come to carry four cubits in a public domain, thereby violating a Torah prohibition.
The rabbis recognize that most people will not choose to abandon their money if they find themselves on the road as Shabbat begins, so they don’t require them to. Better, they reason, to allow a non-Jew to carry it than risk travelers carrying it themselves, which would be a Torah violation.
But the Gemara also records an alternative solution:
The alternative is to move the pouch in increments, each less than four cubits, and thereby carry the object in the public domain without violating a Torah prohibition.
In order to avoid having a non-Jew do the carrying, an alternative is suggested whereby the wallet is carried a distance less than four cubits — the distance one is permitted to carry something in public on Shabbat — placed on the ground, picked up again, and carried another distance less than than four cubits. The process would be repeated until the destination is reached.
This solution avoids the problem of having a non-Jew perform a prohibited action on behalf of a Jew on Shabbat, but it’s also incredibly burdensome. The rabbis are concerned that if this were the rule, people would be unlikely to stick with it, quickly abandoning the incremental approach after a handful of repetitions — assuming they don’t ignore it from the start. So they set it aside in favor of the solution in the mishnah.
It is interesting to note here that human psychology is a determining factor in the development of the rules of Shabbat. In permitting one to give money to a non-Jew or place it on the donkey, the rabbis draw a legal line that serves to protect Shabbat while remaining mindful of how people actually behave. In doing so, they demonstrate an understanding that, if they are to be practiced, the rules of Shabbat must take into account the people who are meant to follow them, even if the resulting rule makes an exception that would not normally be allowed. Deciders of law would be wise to make such practical considerations a part of the legal process.