In Shmot 31:13 we read the words: “You shall speak to B’nai Yisrael saying: Ach- Above all, you must observe my Shabbatot, for it is a sign between Me and you for your generations, to know that I am God who sanctifies you”.

Who will know that through the observance of Shabbat God sanctifies Israel?

Nechama Leibowitz brings two different opinions in order to answer this question:

Rav Saadia Gaon says that the way that a Jew is known is through observance of Shabbat. If he is in town he closes his shop and if he is on the road he doesn’t travel.

In other words, he makes a statement by not working and not traveling.

According to Eben Ezra, Shabbat was not designed as a demonstration to the world, but to implant something into the consciousness of its observers, that we ourselves should know and be made aware of our election, the mission and aim of our existence “that I am the Lord who sanctifies you”.

The phrase “to know” implies that you should know that you are sanctified to Me. We may detect here an allusion to the obligation of every Jew to study Torah… On Shabbat the men and women would visit the prophets and the sages to hear Torah.

Eben Ezra’s point is that we should not just rest on Shabbat but we should put all of our energy into studying Torah, into spiritual advancement which we may not have time for during the week.

We learn from here that Shabbat is not only a break from the regular work week, it is a day to focus on Torah study and spirituality.