One who profanes Shabbat intentionally is subject to death by stoning, if he were forewarned by witnesses, or karet, if he were not, as stated in the Torah. One who desecrates Shabbat unwittingly is liable to bring a sin-offering.
In the halakhic midrash, the Sages derived through exegetical principles that the observance of Shabbat is different from other mitzvot. One who unwittingly performs several primary categories of prohibited labor on Shabbat can be liable to bring several sin-offerings.
According to the accepted halakha, one who sinned unwittingly over the course of many Shabbatot is liable to bring a separate sin-offering for each and every Shabbat on which he performed a transgression because the profaning of each Shabbat constitutes a separate transgression. In the seventh chapter of Massekhet Shabbat, which begins on today’s daf, details of this principle are elaborated. The circumstances in which numerous unwitting transgressions are considered as one transgression and the circumstances in which each Shabbat desecrated is considered to be a separate transgression are determined.
Just as each Shabbat constitutes its own discrete unit, so too the various primary categories of prohibited labor constitute discrete units. Consequently, although all types of creative labor are prohibited by the verse: “You shall not do any manner of labor” (Shmot 20:9), each primary category of prohibited labor is considered a separate prohibition. For example, if one unwittingly performs several primary categories of prohibited labor during one specified time period, he is liable to bring a separate sin-offering for each primary category of prohibited labor violated. It is therefore imperative to ascertain the fundamental parameters of these primary categories of labor in order to ascertain which subcategories are attributed to each. Although other chapters in this tractate deal specifically with several of these categories of labor, the general discussion of this topic is found in this chapter.