Guarding Shabbos Through Redemption
בפסוק שמור את יום השבת
Regarding the verse "Guard the day of Shabbos" (Devarim 5:12).
The Sfas Emes opens with the verse in this parsha that commands us to "guard" the day of Shabbos, the wording used in the second set of the Aseres HaDibros.
השמירה להיות מוכן לקבל קדושת השבת וזה בכח יצ"מ וזכרת כי עבד היית והקב"ה הוציאנו להיות כלי מוכן לקבל קדושת השבת ולכן בפ' זכור לא כ' זה הטעם כי אז היו בתכלית החירות היו מוכנים אל השבת והבינו עיקר בחי' השבת כי ששת ימים עשה כו' וינח ביום השביעי
This "guarding" means to be prepared to receive the kedushah of Shabbos, and this comes through the power of Yetzias Mitzrayim, the Exodus from Mitzrayim. As the verse continues, "And you shall remember that you were a slave" (Devarim 5:15) — Hakadosh Baruch Hu took us out so that we should become a fit vessel, ready to receive the kedushah of Shabbos. This is why in the version of the Aseres HaDibros in Parshas Yisro, the wording of "Remember" (Shemos 20:8), this reason is not written, for at that time Bnei Yisrael were at the ultimate level of freedom; they were already prepared for Shabbos and grasped the essential aspect of Shabbos — "For in six days Hashem made the heavens and the earth... and He rested on the seventh day" (Shemos 20:11).
He explains that "guarding" Shabbos means preparing oneself to be a fit vessel for its kedushah, and that this readiness flows from Yetzias Mitzrayim; the very purpose of Hashem taking us out of Mitzrayim was to make us capable of receiving Shabbos. In Parshas Yisro the Torah omits this reason, because at Matan Torah Bnei Yisrael were already in complete freedom and already grasped Shabbos through the deeper reason of Hashem resting after Creation.
אבל בחי' שמור היא לעולם גם בגלות שאנו רחוקים ממנוחת השבת צריכין לשמור ולהשתוקק אל החירות ע"י זכירת יצ"מ לבא אל בחי' השבת
But the aspect of "guarding" applies for all time, even in galus, when we are distant from the menuchah, the rest of Shabbos; we must guard and yearn for that freedom by means of remembering Yetzias Mitzrayim, in order to come to the aspect of Shabbos.
The dimension of "guarding" is needed in every generation, especially in galus, where we are far from the true menuchah of Shabbos and must actively guard and long for freedom through remembering the Exodus.
ואחז"ל כל שישנו בשמירה ישנו בזכירה:
And Chazal taught that whoever is included in "guarding" is included in "remembering" (Shevuos 20b).
He brings the words of Chazal that the obligation to "guard" and the obligation to "remember" Shabbos are bound together — one who is included in the one is included in the other.
Summary: The Sfas Emes contrasts the two formulations of the Shabbos command in the Aseres HaDibros: "Remember" in Parshas Yisro and "Guard" in our parsha. "Guarding" means making oneself a fit vessel ready to receive the kedushah of Shabbos, a readiness that is rooted in Yetzias Mitzrayim, for Hakadosh Baruch Hu redeemed us precisely so we could absorb the kedushah of Shabbos. At Matan Torah this reason was unnecessary, since Bnei Yisrael stood in complete freedom and already grasped Shabbos through the loftier idea of Hashem's rest after Creation. The aspect of "guarding," however, endures for all time, and especially in galus, when we are distant from the menuchah of Shabbos and must guard and yearn for freedom by remembering the Exodus. This is why Chazal teach that whoever is bound up in "guarding" is likewise bound up in "remembering."