For a leisure journey, the Shulchan Aruch (Siman 248) forbids setting out on a salt sea within the three days before Shabbos, because of oneg Shabbos (the seasickness of the first days). For a mitzvah it is permitted even on a Friday, provided one stipulates with the captain that he will rest on Shabbos (poses imo sheyishbos).
Rivers and short trips have a more lenient regime; the Rema and local custom add further nuances. For a concrete case, ask your Rav.
The Shulchan Aruch forbids setting out on a salt sea less than 3 days before Shabbos for a leisure trip (dvar reshus) — because the discomfort of the first days spoils oneg Shabbos. Two exceptions: a journey for a mitzvah (with a stipulation that he rest on Shabbos), and a short trip where one can arrive before Shabbos. On rivers, where one does not suffer, the regime is more lenient. For a concrete case — ask your Rav.
You book a cruise, a long flight or a departure with a caravan… and the trip runs into Shabbos. Is it permitted to set out? The question feels modern, yet the Shulchan Aruch already addresses it, in Siman 248 of Hilchos Shabbos (Orach Chaim). It speaks of "boarding a ship" (מפליג בספינה) and "traveling with a caravan" (הולך בשיירא), and the reasoning applies directly to our journeys today.
What does the Shulchan Aruch say in Siman 248?
The Mechaber (Rabbi Yosef Karo) opens the siman with the basic rule:
מֻתָּר לְהַפְלִיג בִּסְפִינָה אֲפִלּוּ בְּעֶרֶב שַׁבָּת אִם הוֹלֵךְ לִדְבַר מִצְוָה, וּפוֹסֵק עִמּוֹ שֶׁיִּשְׁבּוֹת. אֲבָל לִדְבַר הָרְשׁוּת אֵין מַפְלִיגִין בִּסְפִינָה בְּפָחוֹת מִג' יָמִים קוֹדֶם הַשַּׁבָּת.
"It is permitted to board a ship, even on a Friday, if one travels for a mitzvah and stipulates with the captain that he will rest on Shabbos. But for a leisure journey, one does not set out less than three days before Shabbos."
In other words: the underlying limit is "no setting out within the 3 days," with two major exceptions that the siman then develops.
The key concepts, explained
1. The three-day rule (ג' ימים קודם השבת)
One does not begin a sea journey within the three days before Shabbos. The Mechaber gives the reason in the next seif: during the first three days at sea, one experiences seasickness and discomfort (צער ובלבול) — so one would enter Shabbos unable to enjoy it, at the expense of oneg Shabbos.
2. דבר מצוה vs דבר רשות — mitzvah or leisure
The three-day limit targets the leisure journey (דבר רשות). A journey for a mitzvah (דבר מצוה) is permitted even on a Friday. The purpose of the trip therefore changes how the rule applies.
3. פוסק עמו שישבות — stipulating the Shabbos rest
For a mitzvah journey, one must stipulate with the captain that he will rest on Shabbos. The Mechaber even adds: "and if in the end he does not stop — it is not a problem" for the traveler, since one did one's part by stipulating it.
Salt sea or river? The distinction of seif ב
Seif ב grounds the rule in oneg Shabbos — and draws a consequence: it applies only to salt seas, where one suffers. On rivers (נהרות), where one does not suffer, it is permitted to board even on a Friday, provided one does not know that the depth is less than ten tefachim (otherwise the prohibition of techumin — going beyond the permitted limits — arises).
The Rema's nuance
The Rema (Rabbi Moshe Isserles, for Ashkenazim) adds an important gloss: more than three days before Shabbos, boarding is permitted, even on a boat drawn by animals along the bank, and even where the Jew will then have to "move the boat forward." He also notes that where the custom is not to board at all on a Friday, even for a short trip, one does not depart from the local minhag.
The cases of the siman (seifim א–ד)
| Seif | Situation | What the source says |
|---|---|---|
| א (1) | Basic rule | No setting out within 3 days for a leisure journey; permitted for a mitzvah with a stipulation to rest |
| ב (2) | Reason for the 3 days | Oneg Shabbos (seasickness); applies only to the salt sea, not rivers |
| ג (3) | קנה שביתה | The question of entering the boat and "acquiring residence" there before Shabbos |
| ד (4) | Caravan (שיירא) and going up to Eretz Yisrael | The special case of the land journey and of aliyah |
Modern application: flight, cruise, train
Now we see why this "old" siman speaks directly of our journeys:
- The cruise most closely resembles the classic case of the ship at sea — the question of oneg Shabbos and the three days arises head-on.
- The long-haul flight and the overnight train raise the same logic: beginning a taxing journey that runs into Shabbos, or one tied to a mitzvah (visiting a sick person, a wedding, going up to Eretz Yisrael…).
- The short trip that lets one arrive before the onset of Shabbos is explicitly treated more favorably by the Mechaber (the example of Tyre to Sidon).
Several contemporary authorities rely on this framework to discuss modern travel before Shabbos — with nuances depending on the minhag, the purpose of the trip and the type of transport.
This article presents what the source says for the purpose of study. It does not rule on any practical case. To know whether your journey is permitted — depending on your community, your situation and the means of transport — ask your Rav.
Frequently asked questions
Can you take a flight or a boat just before Shabbos?
Siman 248 forbids beginning a sea journey on a salt sea within the three days before Shabbos for a leisure trip, because of oneg Shabbos. For a mitzvah it is permitted, with a stipulation to rest on Shabbos. Applying this to flights and cruises depends on the minhag and the case — ask your Rav.
What is the three-day rule (ג' ימים)?
It is the prohibition to board a salt sea less than three days before Shabbos: during the first three days at sea one suffers from seasickness (צער ובלבול) and would enter Shabbos unable to enjoy it. The rule targets only salt seas, not rivers.
Journey for a mitzvah or leisure journey: what is the difference?
For a leisure journey (דבר רשות), the three-day limit applies. For a mitzvah (דבר מצוה), one may board even on a Friday, provided one stipulates with the captain that he will rest on Shabbos. For practice, ask your Rav.
Study Siman 248 in depth
Four levels, from beginner to talmid chacham — Hebrew text, translation, pilpul and the shitah of the Admur HaZaken.