Shabbos Nullifies Natural Dominion
בפ' שמור כו' יום השבת כו' ינוח עבדך כו' כמוך וזכרת כי עבד כו'
In the passage of "Shamor" (Devarim 5:12-15), the Torah says: "the Shabbos day... your servant shall rest... like you, and you shall remember that you were a servant (in the land of Egypt)."
The Sfas Emes opens with the Shabbos commandment in the "Shamor" version of the Aseres HaDibros, which links resting on Shabbos to remembering that Bnei Yisrael were once servants in Egypt.
כי הנה שבת היא נחלה בלי מצרים ולכן שבת זכר ליצ"מ כי א"י לזכות לשבת רק אחר יציאת מצרים לכן שבת לישראל עדות על יצ"מ
For behold, Shabbos is an inheritance without boundaries, and therefore Shabbos is a remembrance of the exodus from Egypt; for one cannot merit Shabbos except after the exodus from Egypt, and so Shabbos is for Bnei Yisrael a testimony to the exodus from Egypt.
He explains that Shabbos is a boundless inheritance, and since it could only be attained after leaving Egypt, Shabbos serves as a standing testimony to the exodus.
והנה כ' אנכי ה"א א' הוצאתיך מא"מ מבית עבדים
And behold, it is written: "I am Hashem your God, Who took you out of the land of Egypt, from the house of bondage" (Shemos 20:2).
He brings the opening of the Aseres HaDibros, where Hashem identifies Himself as the One Who took Bnei Yisrael out of Egypt, from the "house of bondage."
כמ"ש במ"א כי עולם הזה הטבעי נק' בית עבדים כי מעשה בראשית היא להיות ההנהגה בדרך השתלשלות המדרגות זה שליט על זה
As we have explained elsewhere, this natural physical world is called the "house of bondage," because the work of Creation is such that the order of conduct runs by way of a chain of descending levels, this one ruling over that one.
Drawing on his teaching elsewhere, he explains that the natural world is called a "house of bondage" because Creation is structured as a chain of levels, each one ruling over the one beneath it.
ומצד זה היו ג"כ בנ"י עבדים לפרעה
And by reason of this, Bnei Yisrael too were servants to Pharaoh.
Because the world runs through this hierarchy of natural forces, Bnei Yisrael were correspondingly subjugated as servants to Pharaoh.
אבל בשבת קודש מתגלה הנהגה עליונה ובטל כל הממשלות וכחות הטבע
But on the holy Shabbos a higher mode of conduct is revealed, and all the dominions and forces of nature are nullified.
On the holy Shabbos, however, a loftier divine conduct shines forth, and all the natural dominions and forces lose their grip.
וכן הי' ביצ"מ שנתגלה הנהגה עליונה ואפיק לבנ"י מחיובא דכוכבי ומזלי
And so it was at the exodus from Egypt, when a higher mode of conduct was revealed, and He brought Bnei Yisrael out from the bondage of the stars and constellations.
The same thing happened at the exodus, when this higher conduct was revealed and Hashem lifted Bnei Yisrael out from under the rule of the stars and constellations.
ולכן צריך איש ישראל לשבות בשבת כמ"ש ינוח עבדך כו' כמוך להראות כי בטל כל ממשלות בש"ק
Therefore a man of Yisrael must rest on Shabbos, as it is written, "your servant shall rest... like you," to show that all dominions are nullified on the holy Shabbos.
For this reason a Jew must rest on Shabbos, as the verse says his servant shall rest like him, demonstrating that all natural dominions are nullified on the holy day.
וגם איסור עשיות מלאכה היא זאת שבכח אדם לעשות איזה פעולה והתחדשות במלאכת מעשה ידיו
And the prohibition of performing melachah as well is rooted in this: that it lies within a person's power to effect some action and innovation through the labor of his handiwork.
Even the prohibition against doing melachah flows from this idea, since melachah is precisely man's power to produce some new effect through the work of his hands.
ובשבת הכל בטל רק שבו איש תחתיו וזה זכר ליצ"מ:
But on Shabbos all of this is nullified; rather, "each man remained in his place" (cf. Shemos 16:29), and this is a remembrance of the exodus from Egypt.
On Shabbos that power is set aside and each person stays in his place, and this stillness is itself a remembrance of the exodus from Egypt.
Summary: The Sfas Emes explains why the "Shamor" version of the Shabbos commandment ties resting on Shabbos to remembering the exodus from Egypt. The natural world is a "house of bondage" because Creation is built as a chain of descending levels in which each force rules over the one below it, and it was this hierarchy of natural powers that placed Bnei Yisrael under Pharaoh's servitude. At the exodus Hashem revealed a higher mode of conduct that nullifies these natural dominions and lifted Bnei Yisrael out from under the rule of the stars and constellations. The holy Shabbos renews that same revelation, when all the forces of nature are nullified, which is why a Jew must rest. Even the prohibition of melachah expresses this, for melachah is man's power to innovate through his handiwork, and ceasing from it as each man remains in his place is itself a remembrance of the exodus.