Imrei Emet: Shabbat Prayers: “Am Mekadshei Shevii”
“The people that sanctifies the seventh day, they will all be satisfied and delighted from Your goodness.” Is not the Sabbath holy in and of itself? To what do we refer when we describe, “the people that sanctifies the seventh day?” We can understand this as referring to the people who are able to insert the Shabbat sanctity throughout the week; they are adding to the Shabbat sanctity all the time.
We can take this another step: just as there is a concept of adding on to the Shabbat, adding time from Friday onto the Sabbath, and from Saturday night onto the Sabbath, so too there is a concept to add on to the Sabbath within itself; such as even things that are permissible to think about on the Sabbath, if one is so moved by the holiness of the day that he refrains even from such permissible thoughts, he is adding on to the the Sabbath sanctity. It is to such a person that we refer when we describe, “The people that sanctifies the seventh day.” Imrei Emet