Shabbos as Testimony to Hashem
בפסוק אתה הראת לדעת כו'
On the pasuk, "You have been shown to know" (Devarim 4:35).
The Sfas Emes opens with the pasuk in which Hashem showed Bnei Yisrael open revelation so that they would come to a clear knowledge of Him.
פרש"י פתח להם עליונים ותחתונים כו'
Rashi explains: He opened up for them the upper worlds and the lower worlds, and so forth.
Rashi teaches that at this revelation Hashem tore open the upper and lower worlds so that Bnei Yisrael could see that He is the One and only.
פי' כל חשכות הטבע אינו עומד בפני איש ישראל עובד ה' ומתפתח לו בכ"מ הפנימיות לכן נבראו בנ"י להעיד עליו ית'
The meaning is that all the darkness of nature does not stand in the way of a Jew who serves Hashem, and for him the inner dimension opens up in every place; therefore Bnei Yisrael were created to bear witness to Him, may He be blessed.
He explains that a Jew who serves Hashem is not blocked by the concealment of the natural world; the inner Godliness opens up to him everywhere, and this is the very purpose for which Bnei Yisrael were created, to testify to Hashem.
ופי' לדעת להעיד ולברר האמת בעולם
And the meaning of "to know" is to bear witness and to clarify the emes in the world.
Thus "to know" means actively bearing witness and bringing the truth of Hashem to light in the world.
וכן במצות השבת דכתי' וזכרת כי עבד היית כו' ושם כתי' כי בו שבת
And so too regarding the mitzvah of Shabbos, where it is written, "And you shall remember that you were a slave [in Mitzrayim]" (Devarim 5:15), and there too it is written, "for on it He rested" (Shemos 20:11).
He links this to Shabbos, which the Torah ties both to Yetzias Mitzrayim and to Hashem's resting after Creation, two reasons that seem distinct.
רק הוא דבר אחד כי שבת סהדותא אקרי דכתי' ג"כ לדעת במצות שבת בפ' תשא
But it is really one matter, for Shabbos is called "a testimony," as it is likewise written "to know" in the mitzvah of Shabbos in Parshas Ki Sisa (Shemos 31:13).
He resolves that the two are really one theme, since Shabbos itself is called a testimony, and the Torah uses the same language of "knowing" by the mitzvah of Shabbos in Parshas Ki Sisa.
והוא כנ"ל דבימי המעשה הכל מלובש בטבע כמ"ש ששת ימי המעשה יהי' סגור ובש"ק נגלה הפנימיות
And this is as stated above, that during the days of work everything is clothed in nature, as it is written, "the six days of labor it shall be shut" (Yechezkel 46:1), and on the holy Shabbos the inner dimension is revealed.
During the workweek the inner Godliness is hidden inside nature, but on Shabbos that concealment is opened and the inner dimension is revealed.
וכמו כן ביצ"מ הראה הש"י כוחו וגבורתו לשנות הטבע וכיון שהוציאך כו' ע"כ יש ביכולת איש ישראל לברר עדות הנ"ל לכן צוך לעשות השבת:
And likewise at Yetzias Mitzrayim Hashem revealed His power and might to change nature, and "since He took you out," and so forth, therefore it is within the ability of a Jew to clarify the aforementioned testimony; this is why He commanded you to keep the Shabbos.
Just as Hashem broke the bounds of nature at Yetzias Mitzrayim, He gave a Jew the power to reveal and testify to that same truth, which is why He commanded us to keep Shabbos.
Summary: The Sfas Emes explains that the great revelation of "You have been shown to know" was meant to bring Bnei Yisrael to a clear recognition of Hashem, for which they were created to bear witness to Him and clarify the emes in the world. A Jew who serves Hashem is not held back by the concealment of nature; the inner Godliness opens up to him in every place. On this basis he reconciles the two reasons the Torah gives for Shabbos, Yetzias Mitzrayim and Hashem's resting from Creation, showing they are one theme, since Shabbos itself is called a testimony. During the six days of work everything is clothed in nature, while on Shabbos the inner dimension is revealed. Just as Hashem changed nature at Yetzias Mitzrayim, He empowered every Jew to reveal and testify to that truth, which is precisely why He commanded us to keep Shabbos.