The Mitzvah of Oneg Shabbos is to delight in Shabbos by eating enjoyable foods. The sages teach that one who delights in Shabbos will receive an “unlimited inheritance”, be freed from servitude to the nations and will be granted all of their heart’s desires.
The Gemara gives the example of eating large fish, garlic and cooked beets. If one cannot afford such delicacies, Rav Pappa teaches that one can even serve Kasa Deharsena – a dish made with small fish fried in oil and flour.
To illustrate the reward for delighting in Shabbos, the Gemara tells the story of Rabbi Yossi Mokir Shabbos. Yosef found a treasure inside of a large fish that he bought in honour of Shabbos at great expense.
The Rishonim and Acharonim explain that whilst the Gemara lists certain foods, these are only examples of foods which were considered delicacies in the times of the sages of the Gemara. One fulfills the Mitzvah by eating whatever is considered a delicacy in their time and locale.
The Alter Rebbe writes that unlike on Yomtov, on Shabbos there is no obligation to eat meat and drink wine. The Shulchan Aruch only writes that one should serve meat and wine because we assume that most people enjoy eating meat and drinking good wine. Someone who does not enjoy meat need not eat it on Shabbos.
So therefore, whilst the sages give the example of eating fish on Shabbos, the Alter Rebbe states emphatically, that there is no Halachic basis in Niglah (the Talmudic-Halachic part of Torah) for specifically eating fish on Shabbos.
This wording implies that whilst according to Niglah there is no basis, according to Nistar - the hidden Kabbalistic teachings, there are reasons for eating fish on Shabbos. The Kitzur Shelah writes that eating fish at each of the three Shabbos meals is a great matter.
The Magen Avraham quotes from Tikunei Shabbos that one should eat fish at all three of the Shabbos meals. The Mishna Berura writes that this is a good practise.
The Alter Rebbe in his Siddur writes that it is good to eat fish at the Shalosh Seudos meal more so than the other Shabbos meals. Kaf Hachaim writes that this is based on the Kabbalistic teachings of the Ariza”l and that if one only has a small amount of fish, it should be served for Shalosh Seudos and only a small amount should be eaten at the other Shabbos meals. The Ben Ish Chai also writes that it is a Mitzvah to eat at least a small amount of fish at Shalosh Seudos.
Response to Price Gouging
The Magen Avraham writes that if the non-Jews deliberately raise the price of fish, the community should make a Takanah (decree) that no one should buy fish. The Alter Rebbe explains that even if only some people will not be able to afford fish, the Takanah should be made to forbid anyone from buying fish, even if they can personally afford it. This way, the merchants will be forced to lower their prices.
The Ba’er Heitev quotes Beis Hillel that this only applies if the price is raised by more than a third. If the price gouge is a third or less, then one must still buy fish for Shabbos. This is based on the Halacha that one must spend up to a third extra for a Hiddur Mitzvah.
In Kuntres Acharon, the Alter Rebbe writes that the Beis Hillel’s opinion is based on his view, that eating fish on Shabbos is Biblically required. The Alter Rebbe questions this as the Torah does not mention eating fish. Even Rabbinically there is no source in Niglah that one must eat fish on Shabbos. Even though the Gemara mentions eating fish, this is going beyond the letter of the law and one can always fulfill the Mitzvah of Oneg Shabbos with other foods. Therefore, no comparison can be made to the requirement of spending up to a third extra for Hiddur Mitzvah.
According to the Alter Rebbe, the Takanah should be decreed even if the price increases are smaller. This is also the position of Elya Rabbah, Pri Megadim and Mishna Berura.
Whilst there are opinions that Oneg Shabbos is Mideoraisa, it is accepted by most of the Poskim and Rishonim that Oneg Shabbos is a Mitzvah from the Neviim.
Reasons why we eat Fish on Shabbos
The Ariza”l teaches that the souls of Tzaddikim are reincarnated in fish.
The Bnei Yissaschar writes that fish were blessed by Hashem on the fifth day of Creation. Man was blessed by Hashem on the 6th day of Creation. The Shabbos day was blessed by Hashem on the seventh day. When we eat fish on Shabbos, there is a threefold blessing of the three days together.
Mateh Moshe writes that the Shabbos meal is a taste of the Seudah which will be served to the Tzaddikim when Moshiach comes. At this meal we will eat from the Leviason fish.
Minchas Yaakov writes that fish do not have eyelids and so their eyes are constantly open. This alludes to the fact that Hashem’s eyes are always open to look after those who fear Him, with abundant mercy. Based on this some Tzaddikim would eat from the eyes of the fish.
The Ben Ish Chai writes that whereas the animals were created from the earth, fish were created from the water. Water is the loftiest of the four elements. Since on Shabbos we receive sustenance from the highest spiritual levels, it is better to eat fish on Shabbos than meat.
The Ben Ish Chai offers another explanation based on Parshas Behaalosecha. When the Jewish people complained that they wished to eat meat, Hashem said that He would give them meat to eat for a month of days, until they would become sickened by it. Moshe responded “if all of the sheep and cattle were slaughtered... if all of the fish of the sea were gathered would it suffice for them?”
From this we learn that whilst meat requires Shechitah, fish do not need to be slaughtered to render them kosher. Fish only require gathering. Unlike meat which requires an action of Melacha to prepare it, on Shabbos the Tikun (spiritual fixing of the world) is effected without requiring any Melacha, like fish which do not require Shechitah.
The Sefer Otzar Yad Chaim records that the custom of old was to first eat meat and afterwards to eat fish. This is alluded to in the Zemiros of Shabbos בשר ודגים וכל מטעמים, “to eat meat, fish and all types of delicacies”. However, based on the Ram-bam that one should eat more easily digested foods before heavier foods, one should eat the fish before meat.
