Shabbat represents a “taste of the World to Come” (מעין עולם הבא), a taste of the pleasure inherent in the future reality, represented by the sefirah of understanding. Although we tend to associate the holiness of Shabbat with wisdom—a state described by the sages as “Shabbat is already sanctified,” as explained in Chasidic teachings, there is another aspect of Shabbat described by the verse, “the Children of Israel with guard the Shabbat, making the Shabbat.” This verse represents bringing the holiness of Shabbat instantiated from Above, from wisdom to understanding.
Likewise, during the time of the third meal, the light of the crown is brought to understanding and we can experience a taste of the World to Come, which is why the custom by many is not to eat at all (or to eat lightly) during this time, tasting from the World to Come when there will be no need to either eat or drink.
This commandment, as it corresponds to understanding, thus enables us to envision the future pleasure of the World to Come within our own reality specifically on Shabbat.
