What is the inner meaning of the statement "Behold God gave you the Shabbat" (Exodus 16:29)?
After all, we have claimed that a person makes his own Shabbat, preparing it both by his work during the week and his mitzvot.
Someone who took no anticipatory trouble would not receive anything.
The joy of the Sabbath depends on the work put into the performance of mitzvot for the whole week, which could indicate that the profane as well as the spiritual create the holiness of Shabbat.
Its delight rests on material preparations as well as on upright conduct.
We could conclude, therefore, that the meaning of the statement lies in the addition of the word your Shabbat, pointing out that God gave each his own Shabbat.
The day of rest is ours to do with as we like.
That is, we may react as we choose to the gracious gifts of Torah and mitzvot, and then, in addition, and in accordance with our choice, we are given a Shabbat of our own making.
–Rabbi Adin Steinsaltz
From "Hidden Aspests of Shabbat," chapter 6, in The Candle of God by Rabbi Adin Steinsaltz