Shabbos 7:2-3

Shabbos 7:2

There are 39 categories of labor on Shabbos: (agricultural labors include) planting, plowing, reaping, binding sheaves, threshing, winnowing, sorting, grinding, sifting, kneading, baking; (textile labors include) shearing, bleaching, beating wool, dyeing, spinning, stretching the warp, making the loops, weaving two threads together, separating two threads, tying, untying, sewing two stitches, tearing in order to sew two stitches; (labors of preparing hides include) trapping, slaughtering, skinning, salting, curing the hide, scraping, cutting; (other labors include) writing two letters, erasing in order to write two letters, building, demolishing, extinguishing, kindling, the final hammer blow (i.e., completion) and transporting between different domains.

Shabbos 7:3

Another rule of Shabbos is that if something is fit to be safeguarded and people do, in fact, safeguard it, then if someone inadvertently carried this item between domains on Shabbos, he must bring a sin offering (even if the item is not significant to him personally). If something is not fit to be safeguarded and people don’t generally safeguard it, if someone transported this item between domains on Shabbos, he need not bring a sin offering, but an individual who does safeguard such a thing would have to bring a sin offering for transporting it.