Shabbos remembers and safeguards Torah

זכור ושמור בדיבור אחד.

"Zachor (remember)" and "Shamor (guard)" were said in a single utterance.

Chazal teach that the two formulations of the Shabbos commandment — "remember" and "guard" — were spoken by Hashem simultaneously, in one word.

כל שישנו בשמירה ישנו בזכירה.

"Whoever is included in 'guarding' is included in 'remembering.'"

The two are inseparable: anyone bound by the obligation to guard Shabbos is equally bound by the obligation to remember it.

כי זכור נאמר לאנשים גדולי הערך אשר בהזכירם את יום השבת מוסיפין לו קדושה כמ"ש לקדשו.

For "Zachor" was said to people of great stature, who, by remembering the day of Shabbos, add holiness to it, as it is written, "to sanctify it (l'kadsho)."

"Remember" is the loftier, active service — fit for elevated people who, through their very remembrance, draw additional kedushah into the day.

וזה הי' עפ"י מדריגה גבוה שהי' לבנ"י בקבלת התורה.

And this was according to the lofty level that Bnei Yisrael possessed at the receiving of the Torah.

This exalted capacity to add holiness to Shabbos corresponds to the elevated madreigah Bnei Yisrael reached at Mattan Torah.

עכ"ז גם ע"י השמירה ששומר עצמו אדם כדי שלא יפגום ח"ו בקדושת שבת עי"ז יש לו שייכות גם בזכירה.

Even so, also through "guarding" — by which a person guards himself so as not to blemish, Heaven forbid, the holiness of Shabbos — through this he gains a share in "remembering" as well.

Even one who serves only at the lower level of "guarding," carefully protecting Shabbos from being diminished, is thereby drawn into the higher avodah of "remembering" and adding holiness.

ועיקר הפי' זכור את יום השבת לקדשו הוא באמת זכירת מתן תורה שאז נתקדשו בנ"י כמ"ש וקדשתם היום ומחר.

And the essential meaning of "Remember the day of Shabbos to sanctify it" is truly the remembrance of Mattan Torah, when Bnei Yisrael were sanctified, as it is written, "and sanctify them today and tomorrow."

At its root, "remembering Shabbos" is bound up with remembering the giving of the Torah, for the days of preparation and sanctification before Sinai are the source of Shabbos's holiness.

ואיתא לכ"ע בשבת ניתנה תורה זכור בעצומו של יום כו'.

And it is taught that according to all opinions the Torah was given on Shabbos — "remember (the Shabbos) on its very day..."

The Gemara establishes that everyone agrees the Torah was given on Shabbos itself, tying the day of Shabbos directly to the day of Mattan Torah.

ופי' שהקב"ה נתן התורה ביום השבת בעבור כי גלוי לפניו ית' כי גם אחר החטא ישאר להם קדושת השבת כאשר חכמים הגידו כי מרע"ה מחזיר לישראל בש"ק הכתרים של הקדמת נעשה לנשמע לכן נתן להם התורה בשבת כדי שיתקיים להם הקדושה ולכן נאמר זכור כו' יום השבת לקדשו בקדושת התורה כנ"ל:

And the explanation is that the Holy One gave the Torah on the day of Shabbos because it was revealed before Him that even after the sin [of the Golden Calf] the holiness of Shabbos would remain with them — as the Sages said, that Moshe Rabbeinu returns to Yisrael on the holy Shabbos the crowns of the precedence of "na'aseh v'nishma (we will do and we will hear)"; therefore He gave them the Torah on Shabbos, so that the holiness would endure for them. And this is why it says, "Remember the day of Shabbos to sanctify it" — with the holiness of the Torah, as explained.

Hashem deliberately gave the Torah on Shabbos because He foresaw that even after the people would sin and forfeit the crowns of "na'aseh v'nishma," Shabbos would remain — and on every Shabbos Moshe restores those crowns to Yisrael. Thus Shabbos permanently safeguards the holiness of Mattan Torah, and "remembering Shabbos to sanctify it" means filling it with that very holiness of Torah.

Summary: "Zachor" and "Shamor" were uttered as one because the two are inseparable: "remember" is the lofty avodah of people who add holiness to Shabbos, mirroring the heights of Mattan Torah, while "guard" protects that holiness — and through guarding one is drawn into remembering as well. At its core, remembering Shabbos is remembering the giving of the Torah, which took place on Shabbos so that even after sin its holiness would endure; every Shabbos, Moshe restores to Yisrael the crowns of "na'aseh v'nishma," and Shabbos forever safeguards the kedushah of Torah.