I’m going to start with a joke I’ve quoted before:
This idea, that a non-Jew cannot keep Shabbat, is from this week’s parasha:
The problem is that this is clearly not the פשט of the pasuk:
And another problem is that there is a better source:
The problem with this, however, is that the reason doesn’t work: Shabbat is a sign between ה׳ and בני ישראל because ה׳ created the world and rested on the seventh day? Creation applies to everyone!
I would read כי in both these places (כי יצר לב האדם רע and כי ששת ימים עשה ה׳ את השמים ואת הארץ) as “despite”, not “because”. ה׳ promises to never curse the world even though the nature of Man is to do evil, and Shabbat is an אות even though ה׳ created the universe, and
the implication of the דרש is that keeping Shabbat is forbidden to human beings; לא ישבתו. The Jewish people were given a special dispensation to observe it, as an אות of their ברית עולם.
I still don’t understand why Shabbat should be forbidden. It is such a good idea:
And it is not obvious that, in fact, a non-Jew is forbidden to observe שבת.
(תוספות disagrees with רש״י, but this makes it clear that גוי ששבת חייב מיתה is more complicated than it looks)
Rav Kaminetsky goes back to the pasuk in our parasha to try to figure this out.
As I understand it, the פשט of יום ולילה לא ישבותו is that, from now on, the laws of nature will not change. We will not see the hand of ה׳ in every aspect of creation. The עומק פשוטו של מקרא, looking at it more deeply, however, is about the past. When we observe the universe, we see that the laws of nature are constant, so when we extrapolate backwards, we may end up with a model of cosmology that starts with a “Big Bang” but it will tell us nothing about how ה׳ actually created the world.
How does that connect to שבת שבת is part of our imitatio dei: just as ה׳ rested from the work of creation, so to do we rest from work. But what acts of מלאכה count as “work”? To abstain from a specific activity is to say that this particular activity was part of the act of creation. And that we can never know.
So I would understand the rule of גוי ששבת חייב מיתה as aggadic, not halachic.
Keeping Shabbat means we have to look into מעשה בראשית, and that is a bad idea.
It represents a breathtaking arrogance about our ability to understand the divine.
And it is dangerous.
So I would understand גוי ששבת חייב מיתה to be like the מתחייב בנפשו in פרקי אבות.
So, שמירת שבת as a way of imitating ה׳ is inherently dangerous. We can’t know what is a מלאכה without understanding מעשה בראשית, and we can’t understand מעשה בראשית. ברית נח assures us that that the laws of physics will appear to be eternal and unchanging, and extrapolating backwards to the Big Bang will not actually tell us anything about בראשית ברא אלוקים.
So how can we keep שבת? That depends on the real nature of ביני ובין בני ישראל אות הוא לעלם. That paragraph is in the context of the מלאכת המשכן. Our imitatio dei is not שבת but the משכן. Just as ה׳ created the world to give space for human beings to exist, so too do we (as כנסת ישראל) create the מקדש to give space for הקב״ה to exist in our world. And just as ה׳ ”rested“ from the “work” of creating the world, so do we rest from the work of creating the מקדש. The ל״ט מלאכות שבת are the tasks used to build the משכן, the task needed to fulfill our role as human beings, and once a week we imitate ה׳ by taking a break from “the practice of keeping up with the predominant social reality”.
As long as we can keep that in mind, our שמירת שבת is safe.