In the Torah portion of No’ach, G-d informs No’ach that after the flood he could expect the seasons to resume and continue on a regular basis, as the verse says (Gen. 8:22), “So long as the earth exists, seedtime and harvest, cold and heat, summer and winter, and day and night shall not cease.”
The Resumption of the Seasons
Rashi explains that during the flood, the seasons ceased as all the heavenly bodies stopped moving. G-d was therefore promising that such a cosmic event would never reoccur. Rather, from this point on, the seasons would proceed normally.
The Beginning of the Seasons
According to Midrash Tanchuma, before the flood there were no seasons. The weather was always mild and pleasant. This pleasant lifestyle contributed to the conceit and hedonism of those generations. After the flood, G-d gave additional hardships to man so that he not become pampered and rebel again. Thus the verse can be understood to mean, “[From now on] for as long as the world exists, [there will be] seedtime, harvest… it will not cease.”
Do Not Cease Working
The Talmud (Sanhedrin 58b) interprets this verse as a command to all of Noah’s descendants (besides the Jewish people) that just as the seasons do not stop, so too they may not cease working. The Hebrew לֹא יִשְׁבֹּֽתוּ is thus translated to mean “They shall not make Shabbat.” In fact, the Talmud says that a gentile who keeps Shabbat is chayav misa (worthy of death). Ravina adds that this applies even if they observe a “Shabbat” (day of rest) on a different day of the week such as Monday.
There are several reasons given by the commentaries as to why a non-Jew may not observe Shabbat:
· A Gift to the Jews
The Midrash compares this matter to a king and queen who are sitting and talking privately and a stranger comes between them and disturbs them. This person would deserve to be punished severely. Similarly, the Shabbat is a private gift that G-d shared with the Jewish people. Therefore, a gentile who comes between the Jewish people and G-d by trying to take this gift for himself is worthy of death. Shabbat is an exclusive gift to the Jewish people as the verse (Exodus 31:17) says, “Between Me and the children of Israel it is forever a sign.”
Even if the gentile observes a “Shabbat” on a Monday he is still detracting from the gift of Shabbat which was given to the Jews as he is proclaiming that the Jews are not unique in receiving this kind of gift.
· Akin to Adultery
Similarly the Zohar (Parshat Pinchas pg. 450) says that the relationship between the Jewish people and the Shabbat is like that of a groom and a bride and thus a gentile observing the Shabbat is akin to adultery.
· Making Their Own Religion
The Rambam writes (Laws of Melachim 10:9), “A gentile who rests even on a weekday, observing that day as a Sabbath, is worthy of death. Needless to say, he is deserving of that punishment if he creates a festival for himself. The general principle governing these matters is that they are not allowed to originate a new religion or create mitzvot for themselves based on their own decisions. They may either become righteous converts and accept all the mitzvot or observe their (seven Noahide) statutes without adding or detracting from them.”
The Rambam seems to be saying that the reason for a gentile not being allowed to observe Shabbat is that it can be viewed as if he is making up his own religion. Certainly, this applies if the gentile makes his day of rest on another day of the week.
· Can Be Mistaken for a Jew
In a similar vein, the Me’iri writes that if a gentile observes Shabbat, Jewish people may mistake him for a Jew and may learn from his (otherwise) idolatrous practices. (It is difficult to understand, according to the Me’iri, how a gentile who observes Shabbat on another day of the week would be mistaken for a Jew. Perhaps he means that the religious practice that he is inventing may be copied by a Jewish person.)
· Time to Sin
The Mishnah (Avot 4:2) says that it is good to study Torah as well as to work since laboring in both will make one too busy to sin. As such, on Shabbat when a Jew may not work, he must occupy himself with Torah study so that he not be tempted to sin. Non-Jews, however, are prohibited from studying Torah. So if they refrain from working on any day of the week, the free time they have can lead them to commit sins since they don’t have the Torah to temper their evil impulses (Divrei Shaul on the Torah by Rabbi Yosef Sha’ul HaLevi Natanzohn).
No Actual Executions
The Rambam writes, “If a gentile studies the Torah, makes a Sabbath, or creates a religious practice, a Jewish court should… punish him (in ancient times). However, he is not to be executed.”
How did Avraham Keep Shabbat?
It is well known that Avraham Avinu (and the other Patriarchs) kept the entire Torah including observing the Shabbat. Since the Torah had not yet been given, it would seem that the patriarchs were considered Noahides. As such, we need to understand how they were allowed to keep Shabbat in light of the above teaching that a non-Jew may not keep Shabbat.
The commentaries offer many explanations. Here are some of them: (See Pardes Yosef and the Metivta Shas for several other explanations.)
· Not a New Religion
According to the Rambam (as quoted above), the reason a gentile may not observe Shabbat is so that they not start their own religion. The status of the patriarchs, and indeed all of the Jewish people before the Torah was given, was that they were a separate nation – a Jewish nation – but that the Torah was not yet mandatory. As such, observing the Shabbat was not considered to be an invention of a new religion since they were the nation that would eventually accept the Torah.
· Not a Secular Day
Rabbi Pinchas Horowitz (in Panim Yafot and HaMakneh on Kiddushin 37b on Tosfot D.H. Mimochorat) explains that until the Torah was given, the day began with the daytime and ended with the nighttime. It was only after the giving of the Torah that each day begins with the nighttime and the daytime follows. At that time it was only forbidden to observe Shabbat if one began in the day and continued into the following night, as the verse says וָלַ֖יְלָה לֹ֥א יִשְׁבֹּֽתוּ d י֥וֹם and night (in that order) you shall not observe Shabbat.
Since Avraham observed Shabbat the way we do today, beginning with Friday night and ending with nightfall on Shabbat afternoon, this was not a violation of the above rule.
· He Wore Tzitzit
Some explain that Avraham was able to keep Shabbat as a Jew while simultaneously violating it in terms of the laws that apply to gentiles because he wore tzitzit. When a Jew wears tzitzit, they are considered adornments since he is fulfilling a mitzvah by wearing them. As such, he is not considered to be “carrying” his tzitzit strings but rather “wearing” them. If a gentile wears tzitzit, on the other hand, since for him it is not a mitzvah, it is considered as if he is “carrying” them rather than “wearing” them. As such Avraham was not keeping Shabbat as defined by the halachot relevant to non-Jews since he was wearing tzitzit which, by those standards, is considered carrying.
· Defining Work
The definition of work on Shabbat for a Jew is to do one of the 39 forbidden types of labor (G-d forbid). Whereas for a gentile, the definition is to perform hard, arduous tasks. As such, it is possible that the patriarchs “worked” on Shabbat by moving heavy objects and similar activities and thus did not transgress any forbidden labor on Shabbat. Nor did they “rest” on Shabbat since they were busy with other types of work.
For a Convert
When non-Jews are preparing for conversion to Judasim, they are encouraged to observe the mitzvot for the sake of practice. Nevertheless, they should not observe a Shabbat fully until after they convert.
After the Brit Milah
If a man has already had a brit milah for the sake of conversion but has not yet immersed in the mikvah, he may (and should) observe Shabbat. Several reasons are given for this:
· Since he has the covenant of the brit, he should observe the covenant of the Shabbat.
· Our forefathers in the desert began observing Shabbat before they had immersed in the mikvah but after they had already had their brit milah.
· The brit milah has already cleansed him from the impurity of the gentiles although he doesn’t yet have the holiness of a Jew.
Must do Teshuvah Before Shabbat
The holy Sefarim write that one should do Teshuvah on Fridays, before Shabbat. The Gerrer Rebbe (Imrei HaRim Gen. 2:3) explained that the sins that we have transgressed are like a foreign (non-Jewish) entity within ourselves. As such, we must get rid of this entity before Shabbat so that we don’t have a gentile (within us) keeping Shabbat.
May we merit to observe Shabbat in a state of holiness and purity.
 Devarim Rabbah 1:21 and Shenot Rabbah 25:11
 Reb Chaim Brisker in Chidushei HaGrach Siman 436. He proves that the “Hebrews” already had the status of being Jewish before the giving of the Torah from the fact that the Talmud (Sanhedrin ibid) says that Moshe killed the Egyptian taskmaster because he had hit a Jew. And a gentile who hits a Jew deserves to die. Thus we see that the Jews had the status of being Jewish at that time although they had not yet received the Torah.
 The Pardes Yosef questions this based on the refrain in the beginning of Genesis “וַיְהִי. עֶרֶב. וַיְהִי. בֹקֶר. יוֹם. אֶחָד It was evening it was morning, day…” which seems to mean that each day is comprised of evening then morning. But see Rashbam on Gen. 1:5 (this commentary of the Rashbam on the first several portions of the Torah was omitted in some printings) who interprets the verse to mean “the sun set and then the morning began and the day was completed.” I.e., at the beginning of creation each day began with the daytime and ended at the end of the nighttime (just when the next day was breaking).
 See sources brought in Pardes Yosef and the Metivta Shas on Sanhedrin ibid.
 Reb Chaim Brisker questions this since Avraham was, in fact, keeping the mitzvot as a stringency. So, even if he was, technically, a gentile, the tzitzit would still be considered an ornament since they aid his spiritual growth.
 Rabbi Yakov Ettinger in Responsa Binyan Tziyon, 91
 The Shevet HaLevi 7:162 quotes the Tosfot Yeshanim that a gentile who is training to convert may already observe the Shabbat. But this is not the accepted halacha.
 Binyan Tziyon ibid and many other sources quoted in Margaliyot HaYam on Sanhedrin
Wishing you a Shabbat Shalom UMevorach!