Jewish law (halakha) prohibits doing any form of
melakhah (מְלָאכָה, plural
melakhoth) on Shabbat, unless an urgent human or medical need is life-threatening. Though
melakhah is commonly translated as "work" in
English, a better definition is "deliberate activity" or "skill and craftmanship". There are 39 categories of
melakhah: • plowing earth • sowing • reaping • binding sheaves • threshing • winnowing • selecting • grinding • sifting • kneading • baking • shearing wool • washing wool • beating wool • dyeing wool • spinning • weaving • making two loops • weaving two threads • separating two threads • tying • untying • sewing stitches • tearing • trapping • slaughtering • flaying • tanning • scraping hide • marking hide • cutting hide to shape • writing two or more letters • erasing two or more letters • building • demolishing • extinguishing a fire • kindling a fire • putting the finishing touch on an object, and • transporting an object (between private and public domains, or over 4
cubits within public domain) The 39
melakhoth are not so much activities as "categories of activity". For example, while "winnowing" usually refers exclusively to the separation of
chaff from
grain, and "selecting" refers exclusively to the separation of debris from grain, they refer in the Talmudic sense to any separation of intermixed materials which renders edible that which was inedible. Thus, filtering undrinkable water to make it drinkable falls under this category, as does picking small bones from fish (
gefilte fish is one solution to this problem). The categories of labors prohibited on Shabbat are
exegetically derived – on account of Biblical passages juxtaposing Shabbat observance () to making the
Tabernacle () – that they are the kinds of work that were necessary for the construction of the
Tabernacle. They are not explicitly listed in the Torah; the Mishnah observes that "the laws of Shabbat ... are like mountains hanging by a hair, for they are little Scripture but many laws". Many
rabbinic scholars have pointed out that these labors have in common activity that is "creative", or that exercises control or dominion over one's
environment. In addition to the 39
melakhot, additional activities were
prohibited by the rabbis for various reasons. The term
shomer Shabbat is used for a person (or organization) who adheres to Shabbat laws consistently. The (strict) observance of the Sabbath is often seen as a benchmark for orthodoxy and indeed has legal bearing on the way a Jew is seen by an
orthodox religious court regarding their affiliation to Judaism.
Specific applications Electricity . The cap can be twisted, which covers the lightbulb with a dark shell and dims the light in a way arguably acceptable on the sabbath Orthodox and some Conservative authorities rule that turning
electric devices on or off is prohibited as a
melakhah; however, authorities are not in agreement about exactly which one(s). One view is that tiny sparks are created in a switch when the circuit is closed, and this would constitute lighting a fire (category 37). If the appliance is purposed for light or heat (such as an
incandescent bulb or electric oven), then the lighting or heating elements may be considered as a type of fire that falls under both lighting a fire (category 37) and cooking (i.e., baking, category 11). Turning lights off would be extinguishing a fire (category 36). Another view is that completing an electrical circuit constitutes building (category 35) and turning off the circuit would be demolishing (category 34). Some schools of thought consider the use of electricity to be forbidden only by
rabbinic injunction, rather than a
melakhah. A common solution to the problem of electricity involves preset timers (
Shabbat clocks) for electric appliances, to turn them on and off automatically, with no human intervention on Shabbat itself. Some Conservative authorities reject altogether the arguments for prohibiting the use of electricity. Some Orthodox also hire a "
Shabbos goy", a non-Jew (who must not be regularly employed by the household in question) to perform prohibited tasks (like operating light switches) on Shabbat.
Automobiles Orthodox and many Conservative authorities completely prohibit the use of automobiles on Shabbat as a violation of multiple categories, including lighting a fire, extinguishing a fire, and transferring between domains (category 39). However, the Conservative movement's
Committee on Jewish Law and Standards permits driving to a synagogue on Shabbat, as an emergency measure, on the grounds that if Jews lost contact with synagogue life, they would become lost to the Jewish people. A halakhically authorized
Shabbat mode added to a power-operated
mobility scooter may be used on the observance of Shabbat for those with walking limitations, often referred to as a Shabbat scooter. It is intended only for individuals whose limited mobility is dependent on a scooter or automobile consistently throughout the week.
Modifications Seemingly "forbidden" acts may be performed by modifying technology such that no law is actually violated. In
Sabbath mode, a "
Sabbath elevator" will stop automatically at every floor, allowing people to step on and off without anyone having to press any buttons, which would normally be needed to work. (
Dynamic braking is also disabled if it is normally used, i.e., shunting energy collected from downward travel, and thus the
gravitational potential energy of passengers, into a
resistor network.) However, many rabbinical authorities consider the use of such elevators by those who are otherwise capable as a violation of Shabbat, with such workarounds being for the benefit of the frail and handicapped and not being in the spirit of the day. Many observant Jews avoid the prohibition of carrying by use of an
eruv. Others make their
keys into a
tie bar, part of a
belt buckle, or a
brooch, because a legitimate article of
clothing or
jewelry may be worn rather than carried. An elastic band with clips on both ends, and with keys placed between them as integral links, may be considered a belt.
Shabbat lamps have been developed to allow a light in a room to be turned on or off at will while the electricity remains on. A special mechanism blocks out the light when the off position is desired without violating Shabbat. The
Shabbos App is a proposed
Android app claimed by its creators to enable
Orthodox Jews, and all Jewish Sabbath-observers, to use a
smartphone to text on the Jewish Sabbath. It has met with resistance from some authorities.
Permissions If a human life is in danger (pikuach nefesh), then a Jew is not only allowed, but required, to violate any halakhic law that stands in the way of saving that person (excluding murder, idolatry, and forbidden sexual acts). The concept of life being in danger is interpreted broadly: for example, it is mandated that one violate Shabbat to bring a woman in active labor to a hospital. Lesser rabbinic restrictions are often violated under much less urgent circumstances (a patient who is ill but not critically so). Various other legal principles closely delineate which activities constitute
desecration of Shabbat. Examples of these include the principle of
shinui ("change" or "deviation"): A violation is not regarded as severe if the prohibited act was performed in a way that would be considered abnormal on a weekday. Examples include writing with one's nondominant hand, according to many rabbinic authorities. This legal principle operates ''bedi'avad
(ex post facto'') and does not cause a forbidden activity to be permitted barring extenuating circumstances.
Reform and Reconstructionist views Generally, adherents of
Reform and
Reconstructionist Judaism believe that the individual Jew determines whether to follow Shabbat prohibitions or not. For example, some Jews might find activities, such as writing or cooking for
leisure, to be enjoyable enhancements to Shabbat and its holiness, and therefore may encourage such practices. Many Reform Jews believe that what constitutes "work" is different for each person, and that only what the person considers "work" is forbidden. The radical Reform rabbi
Samuel Holdheim advocated moving Sabbath to Sunday for many no longer observed it, a step taken by dozens of congregations in the United States in late 19th century. More rabbinically traditional Reform and Reconstructionist Jews believe that these
halakhoth in general may be valid, but that it is up to each individual to decide how and when to apply them. A small fraction of Jews in the Progressive Jewish community accept these laws in much the same way as Orthodox Jews. ==Encouraged activities==