Shabbos and the Exodus contain the whole Torah

כתיב בשבת זכור ושמור.

It is written regarding Shabbos "zachor" (remember) and "shamor" (guard).

The two versions of the Aseres HaDibros express Shabbos through two complementary commands — a positive remembering and a protective guarding.

ואיתא בזוה"ק שהוא כולל כל התורה מצות עשה ומצות ל"ת.

And it is brought in the Zohar HaKadosh that this includes the entire Torah — the mitzvos asei (positive commandments) and the mitzvos lo saaseh (prohibitions).

"Zachor" corresponds to all the positive mitzvos and "shamor" to all the prohibitions, so that Shabbos contains the whole Torah in miniature.

וכמו כן ביציאת מצרים כתיב זכור כו' היום הזה וכתיב למען תזכור כו' יום צאתך.

And likewise regarding Yetzias Mitzrayim it is written "Remember… this day," and it is written "so that you remember… the day of your going out."

The very same lashon of "zachor" that defines Shabbos is used for the Exodus, hinting that Yetzias Mitzrayim too carries the dimension of remembering.

וכתיב בי' ג"כ שמור כו' חודש האביב.

And it is written regarding it (the Exodus) as well "shamor" (guard)… "the month of springtime."

The Exodus also carries the lashon of "shamor," as in "Guard the month of Aviv" — the command to watch over and protect.

ושמרתם את המצות.

"And you shall guard the matzos."

The word "matzos" can be read as "mitzvos" — guard the mitzvos — so this posuk too pairs the dimension of "shamor" with Yetzias Mitzrayim.

כי יצ"מ ג"כ כולל כל התורה.

For Yetzias Mitzrayim, too, includes the entire Torah.

Just like Shabbos, the Exodus contains within it both "zachor" and "shamor," and therefore the whole Torah is bound up in it.

לכן כתיב אשר הוצאתיך מארץ מצרים:

Therefore it is written "Who took you out of the land of Mitzrayim."

The Dibros open by recalling the Exodus precisely because Yetzias Mitzrayim, like Shabbos, is the root and container of all the mitzvos that follow.

Summary: Both Shabbos and Yetzias Mitzrayim contain the entire Torah, because each carries the twin dimensions of "zachor" (the positive mitzvos) and "shamor" (the prohibitions); this is why the foundation of all the mitzvos is rooted in the memory of the Exodus.