Welcome to Embrace Shabbat.
The Gemara (Shabbat 31a) cites the passuk וְהָיָה אֱמוּנַת עִתֶּיךָ חוֹסֶן יְשׁוּעוֹת חׇכְמַת וָדָעַת וְגוֹ and brings two different explanations.
First, it draws a connection between each word of the passuk the tractates of the Mishnah:
אֱמוּנַת corresponds to זְרָעִים
עִתֶּיךָ corresponds to מוֹעֵד.
חוֹסֶן corresponds to נָשִׁים.
יְשׁוּעוֹת corresponds to נְזִיקִין
חׇכְמַת corresponds to קׇדָשִׁים, and
דָעַת corresponds to טְהָרוֹת.
Lastly it says: יִרְאַת ה׳ הִיא אוֹצָרוֹ, fear of Hashem is the treasure house.
The Gemara then brings an alternative explanation. After 120, a person is brought for judgment in the next world and is asked six questions. The Vilna Gaon teaches that the six words of this passuk also correspond to the six questions asked at this time of judgment.
- Did you deal honestly in business? This corresponds to אֱמוּנַת.
- Did you set aside time for Torah?
- Did you try to have children?
- Did you look forward to G-d’s salvation?
- Did you get involved in wisdom and 6. understand one thing from another?
Again, all of that only works if יִרְאַת ה׳ הִיא אוֹצָרוֹ, Yirat Hashem is your treasure house.
That is why the first word of the Torah is בראשית, which, when scrambled, spells ירא שבת. According to the Yalkut Reuveini, Shabbat brings Yirat Shamayim.
Similarly, there were seven candles on the Menorah in the Beit HaMikdash. Three branches jutted out on each side, corresponding to the six days of the week; the branch in the middle corresponded to Shabbat.
In his sefer Yafei LaLev (letter 78), Rav Chaim Palagi teaches that when a person keeps Shabbat, he comes to recognize that Hashem created the world and continues to controls it. Shabbat, the seventh day, corresponds to the 7000th year, which is Olam Haba, יום שכולו שבת. When a person realizes that G-d created the world and continues to control it and that there is reward and punishment, it will bring him to develop Yirat Shamayim- and that creates the treasure house to store all Torah and Mitzvot.
Further, the Gemara tecaches that HaKadosh Baruch Hu tells us: מתנה טובה יש לי בבית גנזי ושבת שמה, I have a special present in My treasure house and it is called Shabbat. Another Gemara teaches that G-d has Yirat Shamayim in His treasure house. So which one is it- does G-d have Shabbat or Yirat Shamayim in His treasure house?
The answer is that it is one and the same- the treasure house with Shabbat is the treasure house of Yirat Shamayim. The only way to store Torah is with Yirat Shamayim. (One who is interested in learning more about this concept can look at Nefesh HaChaim, Shaar Daled, Chapters 4-6, where he discusses at length that you need Yirat Shamayim in order to keep your Torah preserved.)
Shabbat is the preservative of everything that we do during the week, because Shabbat brings us to develop the critical quality of Yirat Shamayim.
Have a Shabbat Shalom.