The thirteenth perek of Massekhet Shabbat that begins on today’s daf discusses two groups of primary categories of labor [avot melakhot]. One section of the chapter deals with the primary category of weaving and related categories of labor. All activities involved in the production of clothing from the spinning of the thread until the final utilization of the yarn; the arrangement of the loom; the weaving itself; and all other improvements made to the fabric, such as dyeing and cleansing it, can be combined by their very nature into one group of categories of labor. They are therefore treated in this chapter as if they were one unit.
The main topic of this chapter is not the description of the nature or parameters of these various labor categories. Rather, it is the establishment of minimal measures for which one is liable should he perform any of these types of labor on Shabbat.
The other section of this chapter deals with the category of trapping, specifically the definition of this category of labor and its parameters. The category of trapping is defined as the confinement of an animal within a space from which it cannot escape. First, however, it must be determined whether or not this prohibition applies to all animals, at which stage in the confinement process the trapping may be said to have been performed, and which methods of confinement may be considered typical modes of trapping for the various species of animals.
The discussion of weaving deals extensively with details of looms that were used in Talmudic times. Among the laws that appear in the first Mishna is the ruling that:
One who makes two meshes, attaching them to either the nirin or the keiros, is liable.
The Gemara asks: What is the meaning of to the nirin? Abayye said: One ties two to the meshes, the thread of the warp, and ties one to the crosspiece, the thread that extends from the weaving rod.
The threads of the warp, the meshes, are tied to the loom, and the weaving of the fabric begins from those two meshes.