When HaShem tells Moshe how His manna will feed the Jewish people, He says, “And on the sixth day they will prepare what they brought, and it will turn out to be twice as much as they gather every day.” (Shemot 16:5.) Of course the people must prepare the manna every day; still, this preparation is mentioned specifically with regard to Shabbat.
This emphasis is echoed later in the same chapter, as Moshe explains to the people, “Tomorrow is a solemn day of rest, holy to Hashem. Bake what you will bake, and cook what you will cook, and everything left over from today leave over and save for tomorrow”. (Shemot 16:23.) Again, the preparation of the manna is mentioned specifically in the context of preparing on Friday for Shabbat.
These verses hint at the special importance of preparing on weekdays for Shabbat. Of course this preparation is partially a matter of practical necessity. Baking and cooking are forbidden on Shabbat, and so if we want cooked food on Shabbat we need to prepare it in advance. “One who toiled on erev Shabbat will eat on Shabbat; but one who didn’t toil on erev Shabbat, what will he eat from on Shabbat?” (Avoda Zara 3a.)
But behind the necessity is a matter of principle. After all, HaShem could have freed us from the need for food one day a week, as He did for the forty days Moshe ascended Mount Sinai without eating or drinking. Or for Shabbat He could have provided special manna which requires no preparation. In both cases, no preparation would need to be done on Shabbat; yet no weekday preparation would be necessary.
Instead, the Torah emphasizes that there is a special importance of preparing on weekdays for Shabbat. Weekdays are not merely days when we may do labors of preparation; they are days which are intended to prepare specifically for Shabbat. The fourth commandment tells us to remember the Sabbath day; our Sages learned that already from Sunday we should have Shabbat in mind (Mechilta Yitro, Mechilta deRashbi Yitro).
Likewise, Shabbat is not merely a day when preparation is forbidden; it is a day which depends on the preparation of weekdays. On Shabbat, we may only use items which were prepared for use already during the week. This is the essence of the “muktze” prohibition, which our Sages based on the verse “they will prepare”. (Pesachim 47b.) By demanding that only items prepared during the week may be handled on Shabbat, we create an interdependence of Shabbat and weekdays. Shabbat is not only different than weekdays, it depends on them; the weekdays are not only different than Shabbat, Shabbat is what gives them direction and meaning.
In all, we have three levels of distinction. In a previous shiur (Chukat), we explained that weekdays are a time of giving, Shabbat a time of receiving. On Shabbat, work which contributes to the world is forbidden, while enjoyment (oneg Shabbat) is mandatory. This principle creates a contrast between weekday and Shabbat.
The mitzva of preparing some Shabbat needs on weekdays, as we did in the desert, sharpens this distinction: Shabbat is specifically a time of receiving from the weekdays; there must be a relationship between weekday and Shabbat.
In the laws of muktze, the Sages sharpen this distinction further: Shabbat is to receive only from the weekdays. Anything which was not ready before Shabbat is muktze and forbidden to use. This addition creates a dependency between weekday and Shabbat.
Given this background, we can easily understand the various categories of muktze: Items which the owner specifically demonstrated are not meant for Shabbat use (the literal meaning of muktze); objects that are not prepared for any use as Shabbat comes in; items which did not even exist as Shabbat came in, like an egg laid on Shabbat (nolad). Rather, we use those objects which were prepared on weekdays, in order to use them on Shabbat.
The 7th Day and the 7th Year
In the shiur on parshat Nitzavim, we pointed out the parallel to shemitta: Like Friday lechem mishneh, the Torah emphasizes that the year preceding sheviit will produce enough to make up for the shemitta shortfall (Vayikra 25:21). Like muktze, the Rabbinical prohibition of sefichin strengthens the dependence of shemitta on regular years, by forbidding most produce which grows by itself in the shemitta year and forcing us to depend on produce grown in previous years. For this also the Sages found a source in the Torah which is from the same section of the Torah dealing with the special blessing of erev Sheviit, hinting that it is an extension of the same idea. (Pesachim 51b.)