IN THE PARSHA:
The עשרת הדברות begin with the words יךָ אַשֶׁר הוֹצֵאתִיךָ מֵאֶׁרֶׁץ מִצְרַיִםקֶׁ אָנֹכִי ד' אֶׁלֹ, I am Hashem your G-d, who brought you out from the land of מצרים.
QUESTION:
Before they left מצרים, and in the days of preparation for מתן תורה, the Yidden were told that they were taken out of מצרים in order to receive the תורה and serve Hashem.
Why does Hashem emphasize again at מתן תורה that He took them out of מצרים to be their G-d?
ANSWER/LIFE LESSON:
The words אָנֹכִי ד' אֶׁלֹקֶׁיךָ mean that we must accept Hashem as our king, and we must therefore obey all of His מצוות, doing what He commands us to do and refraining from what He forbids.
However, this might mean that when one isn’t actively obligated to perform a specific מצוה, he might have his own “freedoms”.
The words אַשֶׁר הוֹצֵאתִיךָ מֵאֶׁרֶׁץ מִצְרַיִם come to teach us something more.
Not only must we obey Hashem’s commands, but we are completely His.
Just as our slavery in מצרים involved our entire being, when Hashem took us out of מצרים our entire being became completely subject – מְשֻׁעְבָד – to Hashem.
Being entirely His means that every part of our being is His, and whatever we do at every moment of every day must be devoted to serving Hashem.
Further discussion:
The above clarifies רש"י’s first explanation on the words אשר הוצאתיך מארץ מצרים.
Why does רש"י bring 2 additional explanations?
(See אות ה in the שיחה)
See שמות פרק ג, פסוק יב and ו-פרק יט פסוקים דיתרו