As we learned on yesterday’s daf there are 39 primary categories of labor that are prohibited on Shabbat. Each one of these types of work is forbidden in its own right, and will require a separate sin-offering if performed unwittingly.
On today’s daf the amora’im discuss the fact that producing a single object may involve several of the prohibited labors and would require multiple sin-offerings.
Rava said: One who unwittingly crafted an earthenware barrel on Shabbat is liable to bring seven sin-offerings. One who crafts an oven is liable for eight sin-offerings, since in addition to those seven labors, he spreads another layer of mortar to finish the job, performing the prohibited labor of smoothing.
In one of the commentaries, the seven sin-offerings are counted as follows:
Removing piles of dirt and thereby leveling the ground, which is a subcategory of (1)
Powdering the dirt, which is a subcategory of (2) grinding;
Removing the pebbles, which is a subcategory of (3) selecting;
(4) kneading the dirt;
(5) cutting it into its shape;
and completing the finished product, which the Mishna calls (7) striking a blow with a hammer (Rav Hai Gaon).
Others suggest a different tally:
(1) Crumbling the dirt;
(2) selecting the pebbles;
(3) sifting with a sieve;
mixing the dirt with water, which is a subcategory of (4) kneading;
(5) smoothing the vessel;
(6) kindling the fire; and
(7) hardening a vessel, which is a subcategory of cooking (Me’iri).
With regard to an oven, according to Rav Hai Gaon, the eighth labor is smoothing, and according to the Me’iri, it is striking a blow with a hammer.
Abayye said: One who unwittingly crafts a receptacle from reeds on Shabbat is liable to bring eleven sin-offerings. And if he sews the mouth of the receptacle, he is liable to bring thirteen sin-offerings.
Some count the eleven sin-offerings as follows:
peeling the reeds, which is (6) threshing;
(8) stretching the warp;
(9) constructing two meshes;
and (11) striking a blow with a hammer (Rav Hai Gaon).
Others claim that peeling the reeds renders one liable for striking a blow with a hammer (ge’onim).
In a case where he sewed the mouth of the receptacle, Rav Hai Gaon argues that one is liable for (12) spinning and (13) sewing.