The Shulchan Aruch (Siman 252) permits starting a melacha on Friday, close to nightfall, that will finish on its own on Shabbos, because a person is not commanded about the "rest of his tools" (shevisas keilim) — the halacha follows Beis Hillel.
Two reservations frame it: no fire one could stoke (shema yechateh), no unsealed pot one could stir (shema yagis). For a concrete case, ask your Rav.
One may start on Friday a piece of work that finishes on its own on Shabbos — soaking, macerating, pressing, irrigating — because according to Beis Hillel inanimate tools need not "rest" on Shabbos (שביתת כלים). The safeguards: no human intervention on Shabbos, no active cooking (שמא יחתה / שמא יגיס), and caution about noise (השמעת קול) and what is publicly visible (מראית עין). For a concrete case — ask your Rav.
You start the washing machine on Friday evening: it runs, spins and stops… in the middle of Shabbos. Is it permitted? The question feels thoroughly modern, yet the Shulchan Aruch already addresses it, in Siman 252 of Hilchos Shabbos (Orach Chaim). It speaks of soaking ink, of bleaching flax in the oven, of loading the press, of opening the water toward the garden — and the reasoning applies directly to our automatic machines.
What does the Shulchan Aruch say in Siman 252?
The Mechaber (Rabbi Yosef Karo) opens the siman with a permission in principle:
מוּתָּר לְהַתְחִיל בִּמְלָאכָה בְּעֶרֶב שַׁבָּת סָמוּךְ לַחֲשֵׁיכָה אַף עַל פִּי שֶׁאֵינוֹ יָכוֹל לְגָמְרָהּ מִבְּעוֹד יוֹם וְהִיא נִגְמֶרֶת מֵאֵלֶיהָ בְּשַׁבָּת.
"It is permitted to begin a melacha on Friday evening, close to nightfall, even if one cannot finish it before night, and it finishes on its own on Shabbos."
Examples follow: soaking ink and dyes, putting flax in the oven to bleach, loading the oil and wine press, opening the water toward the garden. The common point: an autonomous process, which no longer requires the human hand once launched. Three concepts explain why it is permitted — and where the limits are.
The 3 key concepts
1. שביתת כלים — the rest of tools
The founding sugya (Beitzah 16b) sets Beis Shammai, who requires that even a Jew's tools "rest" on Shabbos, against Beis Hillel, for whom only the Jew and those who depend on him (people, animals) rest — not inanimate objects. The halacha follows Beis Hillel.
Consequence: a mechanical process launched on Friday may continue on its own on Shabbos, as the siman sums up: אֵין אָדָם מְצֻוֶּה עַל שְׁבִיתַת כֵּלִים — "a person is not commanded about the rest of his utensils."
2. שמא יחתה / שמא יגיס — the two safeguards
שמא יחתה: "lest one stoke" — if a pot is on the fire, we fear the Jew might revive the embers on Shabbos to speed the cooking. שמא יגיס: "lest one stir" — even off the fire, if the pot is not sealed (טוחה בטיט), we fear one might stir it, since stirring a cooking dish falls under mevashel ("cooking").
This is why wool in a sealed pot, off the fire, is permitted, while anything touching an active cooking remains forbidden.
3. קציצה — the agreed price with the non-Jewish craftsman
The siman (seif ב) permits entrusting one's clothes to a non-Jewish dyer or one's hides to a tanner near nightfall, provided one has agreed on a price (קציצה), that the work is done at his place, and without asking him to work on Shabbos. Thanks to the price, he acts אַדַּעְתָּא דְנַפְשֵׁיהּ — for his own account, not as the Jew's agent (the same logic as in Siman 247).
The cases of the siman (seifim א–ז)
| Seif | Situation | What the source says |
|---|---|---|
| א (1) | Soaking, bleaching, setting traps, loading before nightfall | Permitted if the process is autonomous; forbidden if there is a fire (יחתה) or an unsealed pot (יגיס) |
| ב (2) | Clothes to the non-Jewish dyer / hides to the tanner | Permitted with קציצה, at his place, without an explicit request for Shabbos |
| ג (3) | Work notoriously "Jewish" done in a public place | "טוב להחמיר" — better to be strict (מראית עין) |
| ד (4) | Wearing on Shabbos the garment finished by the non-Jew | Mechaber: permitted (אדעתא דנפשיה); Rema: wait until the end of Shabbos (כדי שיעשה) |
| ה (5) | Irrigation, press, mill, incense, barley to soak | Permitted — the object acts on its own (no shevisas keilim) |
| ו (6) | Going out near nightfall with a needle or a pen | Forbidden — the fear of forgetting and carrying on Shabbos (tefillin permitted) |
| ז (7) | Feeling one's clothes before Shabbos | A mitzvah — so as to carry nothing forbidden on Shabbos |
The Rema's nuance: noise and clock
The Rema (Rabbi Moshe Isserles) adds a precaution about noise (השמעת קול): for a mill that grinds on Shabbos, he reports a strict view ("lest one say: so-and-so's mill grinds on Shabbos") to be followed lechatchilah, while permitting leniency in a case of loss. As for the weight-driven clock that strikes the hours:
וּמוּתָּר לְהַעֲמִיד כְּלִי מִשְׁקוֹלֶת שֶׁקּוֹרִין זייגר מֵעֶרֶב שַׁבָּת, אַף עַל פִּי שֶׁמַּשְׁמִיעַ קוֹל לְהוֹדִיעַ הַשָּׁעוֹת בְּשַׁבָּת, כִּי הַכֹּל יוֹדְעִים שֶׁדַּרְכָּן לְהַעֲמִידוֹ מֵאֶתְמוֹל.
"It is permitted to set going, from the eve of Shabbos, the weight-driven clock called zeiger, even though it strikes to announce the hours on Shabbos, because everyone knows that its way is to be wound the day before."
The principle emerges: when everyone knows that the mechanism was set going before Shabbos, there is no מראית עין.
Modern application: washing machine, timers, machines
Now we see why this "old" siman speaks directly of our appliances:
- The washing machine or dishwasher started on Friday? The principle of שביתת כלים (Beis Hillel) permits it, provided no intervention is required on Shabbos — and subject to audible noise (השמעת קול) and public visibility (מראית עין).
- A programmed cooking robot set to cook on Shabbos? Far more problematic: automatic cooking touches on שמא יגיס and on mevashel. This is a case to put to a Rav.
- Shabbos timers (lights, heating) extend exactly the logic of the zeiger: the mechanism is set before Shabbos and acts on its own.
Several contemporary authorities rely on this framework to discuss automatic machines, with nuances depending on the noise, any cooking involved, and the presence of a manual intervention.
This article presents what the source says for the purpose of study. It does not rule on any practical case. To know whether your appliance or process is permitted — depending on the model, the noise and your community — ask your Rav.
Frequently asked questions
Can you start the washing machine on Friday so it runs on Shabbos?
The siman permits starting work that finishes on its own on Shabbos, because according to Beis Hillel a person is not commanded about the rest of his tools (שביתת כלים). Reservations: no intervention on Shabbos, and caution about noise (השמעת קול) and visibility (מראית עין). For a concrete case, ask your Rav.
What is shevisas keilim (the rest of tools)?
It is the question of whether a Jew's inanimate tools must rest on Shabbos. Beis Shammai requires it; Beis Hillel — whose view is the halacha — does not. This is what permits a mechanical process launched before Shabbos to continue on its own.
Why is a pot on the fire forbidden but a washing machine permitted?
The siman sets two reservations: שמא יחתה (the fear of stoking a fire) and שמא יגיס (the fear of stirring an unsealed pot), which concern cooking. A truly autonomous process, without active cooking or risk of intervention, does not fall under them. For practice, ask your Rav.
Study Siman 252 in depth
Four levels, from beginner to talmid chacham — Hebrew text, translation, pilpul and the shitah of the Admur HaZaken.