Question #1: Carding
"If one of the melachos is carding, does that mean that one may not play cards on Shabbos?"

Question #2: Combing
"Someone told me that combing my hair on Shabbos violates the melachah of menapeitz? Is it prohibited to comb my hair on Shabbos?"

Question #3: Cloth
"Could you please explain the different melachos that involve the creation of cloth?"

Introduction:
Parshas Ki Sisa discusses the laws of Shabbos and of the yomim tovim. We are all aware that there are 39 melachos of Shabbos, and most of us are fairly familiar both with the concepts and with many of the details of such varied melachos as kosheir, tying knots, boreir, selecting, and hotza’ah, carrying. However, there are several melachos, for example, menapeitz, toveh, meisach, oseh batei nirin and potzei’a that are unfamiliar, and perhaps we could say virtually unknown, to most people. Since all of these melachos are involved in the manufacture of textiles, they all apply min haTorah on Shabbos and Yom Tov according to all opinions, which makes a wonderful incentive to study them. I will present these melachos in the order in which they appear in the list of the 39 melachos in the Mishnah in Shabbos (73a).

Menapeitz
Menapeitz is often translated as combing or carding, but neither term explains the melachah adequately. The origin of the word menapeitz means to break something in a way that it scatters (see Radak, Tehillim 2:9), as in the pasuk, ki'chli yotzeir tenapetzeim, "You will shatter them, like a vessel made by a potter." We find the word conveying the same idea in Shoftim (7:19), venafotz hakadim asher biyadam, "They smashed the jugs that were in their hands," and, again, in Yeshayahu (33:3), mei’romemusecha noftzu goyim, "From Your loftiness, nations have dispersed."

The av melachah, or major category, menapeitz, is one of the stages involved in processing wool into a usable textile. The wool shorn from a sheep cannot be used immediately, because it is filthy and very tangled. Cleaning it involves the melachah of melabein, which we will not discuss in this article. Menapeitz includes untangling the wool.

While showering, many people use hair conditioner to facilitate combing the tangles and knots out of their hair. Realize how much more difficult this is for a sheep, whose hair is much curlier, and it has been quite a while since it last brushed its hair! (Wool and hair are essentially the same thing. The word "wool" is used when the hair is soft enough to be used as a textile fabric.) And yet, although the sheep does not care enough about its appearance to warrant using conditioner, combing out the tangles in the wool is absolutely necessary, if one is going to take wool of a sheep or any other animal and spin it into thread. Thus, the definition of the melachah is the separating or combing out of the strands of wool so that they they can be spun into wool (Aruch, eirech nefes; Shu"t Avnei Neizer, Orach Chayim 170:2, 8, 9).

Sheep and other animals
Although the prohibition of shatnez applies exclusively to the hair of sheep and not to the wool of other animals, such as goats, camels, llamas and rabbits (see Kil’ayim 9:1), all opinions agree that menapeitz applies to the wool of all animals that may be used for clothing.

Silk
Although silk, unlike wool, is not hair, and is processed very differently, combing it out on Shabbos, so that it can be spun, also violates the melachah of menapeitz (Rashi, Shabbos 20b s.v. Gushkera).

Sinews
The halachah requires that Sifrei Torah and tefillin be sewn by a strong, very special type of "thread" made of sinew. The processing of these sinews so that they can be used as thread is also considered an act of menapeitz (Rambam, Hilchos Shabbos 9:15).

Linen and cotton
There is a dispute among rishonim whether the melachah of menapeitz applies min haTorah to textile materials that grow from the ground (vegetable-based), such as cotton, jute, or flax, which becomes linen. Rashi and several other early authorities contend that menapeitz applies only to materials that do not grow from the ground (Rashi, Chiddushei Ran and Meiri, all in their commentaries to Shabbos 73b; Tosafos, Shabbos 74a s.v. Af al gav), whereas the Rambam (Hilchos Shabbos 9:12) and the Semag rule that menapeitz applies to all materials. The Chayei Odom rules according to the Rambam that menapeitz does apply to vegetable-based textiles.

Cottonseed
According to several rishonim, combing out cotton, which removes the seeds, violates a different melachah, dosh, threshing, because it separates the usable textile material from the seeds, which are not usable for clothing (Rashi, Shabbos 73b, Ran and Meiri ad locum). The melachah of dosh is violated when one breaks the natural, physical connection between two items that are dissimilar in their use, thus creating a product that can be used easily. For example, threshing breaks the connection between the kernels and the chaff, thus making the kernels usable, and squeezing separates the juice or oil from the fruit. The Chayei Odom concludes that someone who combs out cotton or similar textiles, thus removing the seeds and, at the same time, preparing the fibers for cloth manufacture, violates two melachos, dosh and menapeitz. (However, see Semag who does not seem to agree.)

(Cottonseed is crushed for its oil. At the time of the Gemara, cottonseed oil was used as inferior kindling oil [see Rashi, Shabbos 21a s.v. Mish’cha]. Today, it is a source of cooking oil, used, for example, in the production of potato chips.)

Menapeitz times two
According to some authorities, one can violate the melachah of menapeitz twice on the same material. Certain methods of processing wool involve combing out the material and then soaking it in a special solution, so that it will absorb dye better. This soaking causes the wool to clump again and one needs to comb it out a second time. According to the Maasei Rokei’ach, if both of these actions were performed on Shabbos, this second combing would be a second Torah violation of the melachah of menapeitz (Hilchos Shabbos 9:12).

Carding
Before we go on to the next melachah, let us examine the first two of our opening questions: "If one of the melachos is carding, does that mean that one may not play cards on Shabbos?"

Although many halachic authorities prohibit playing cards on Shabbos (see commentaries to Shulchan Aruch, Orach Chayim 322:6), no one contends that it violates any melachos. As we now see, the melachah called menapeitz has nothing to do with playing cards. It is sometimes called carding because in Old French and Old English the word card means a brush used to disentangle fibers prior to spinning them.

Menapeitz and combing hair
"Someone told me that combing my hair on Shabbos violates the melachah of menapeitz? Is it prohibited to comb my hair on Shabbos?"

There are two questions here. The first is whether combing hair on Shabbos or Yom Tov is included under the melachah of menapeitz. The second is whether it is permitted to comb one’s hair on Shabbos or Yom Tov.

Regarding the first question, the Avnei Neizer demonstrates very conclusively that combing (human) hair is not included under the melachah of menapeitz. The question is why this is true. He proposes that the melachah of menapeitz applies only to hair or wool that is no longer attached to its living source (Shu"t Avnei Neizer, Orach Chayim #171). According to this approach, there could be a prohibition of menapeitz when combing a wig. I will simply comment that, although I have seen many authorities prohibit combing wigs on Shabbos, none of these sources prohibit it because of menapeitz.
A simpler answer is that menapeitz means to prepare fiber so that it can be used as a textile, and that is not the purpose in combing hair (Nimla Tal, menapeitz #15).

Combing hair
Having established that combing your hair does not violate menapeitz, we will now discuss whether it is permitted on Shabbos. According to the Rivash, a rishon who was the av beis din of Algiers in the fourteenth century, it is forbidden to comb your hair on Shabbos. This is because when combing, one pulls out hair, which violates a different melachah of Shabbos, that of gozeiz, which means shearing (Shu"t Harivash #394). This melachah includes any activity that disconnects something connected to a living creature, including clipping nails, shaving, shearing wool, and removing cuticles. The Rivash’s ruling is cited by Shulchan Aruch and later authorities as accepted halachah (Orach Chayim 303:27).

Cloth
At this point, let us discuss the next of our opening questions: "Could you please explain the different melachos that involve the creation of cloth?" To explain them, we need to understand what happens to fiber after it is combed out, until it becomes finished cloth.

Toveh -- Spinning
Toveh is the melachah that immediately follows after menapeitz. The definition of this melachah is taking combed fiber and making it ready to be used for the manufacture of clothing. Spinning combed fiber into thread is the most common application of this melachah, and comprises the av melachah.

Taking a thread and straightening it so that one can sew with it is also included under the melachah of toveh (Shabbos 75a, as explained by Rabbeinu Chananel). Similarly, twisting threads together to make a thicker thread, called shozeir in Hebrew, is also included under the melachah of toveh (Yerushalmi as quoted by Rokei’ach). This process is sometimes colloquially called cabling or plying, although the correct term for it is simply twisting or braiding. Twisting tzitzis threads around themselves, a requirement for the mitzvah, is included under the melachah of toveh and therefore prohibited on Shabbos and Yom Tov (Kitzur Hilchos Shabbos, Chapter 22). Similarly, twisting or braiding fibers into a wick is also included under the melachah of toveh (Shaar Hatziyun 514:52).

Felt
Textile fibers are not always spun into thread. An alternative way of manufacturing fiber into a usable textile is by pressing it -- which makes it into what is called felt. According to the Rambam, the melachah of toveh includes not only spinning fiber into thread, but also pressing fiber into felt (Rambam, Hilchos Shabbos 9:15; cf. Ra’avad ad locum, who explains that manufacturing felt is included under the melachah of boneh and not toveh. Both agree that making felt on Shabbos is prohibited min haTorah). Felt is used as backing to reinforce the shoulder, underarm and neck areas of garments, but one can actually manufacture garments completely out of felt. I have seen blankets, coats, hats and even tents made out of felt.

Meisach
Although many of us have little personal experience with either menapeitz or toveh, we probably have even less experience with the remaining three melachos on our list for today, meisach, oseh batei nirin and potzei’a. Weaving cloth involves several different stages, each of which is its own melachah. Once one has thread, the next stage is creating a warp. This has nothing to do with the shape of a piece of wood. The warp is the "body" of the fabric. One way to create a warp is simply to place the threads onto a loom. One now has a warp through which one can weave threads in a perpendicular direction, thus creating cloth. Placing the threads onto the loom constitutes the melachah of meisach, and weaving other threads through them is the melachah of oreig, weaving.
Here is a second way of performing the melachah of meisach: A common child’s craft involves taking cloth loops and place them onto a specially-constructed metal frame about six or eight inches square. The child then manually weaves other pieces of cloth perpendicularly over and under the loops that are already on the frame. Finally, one crochets the edges and thereby removes the ends of the loops from the metal frame.
When finished, one has created a pretty potholder. In this particular craft, several melachah activities were performed. Placing the loops onto the metal frame creates a warp, and therefore constitutes the melachah of meisach. Weaving the second series of loops through those already on the frame is oreig. It is unclear which melachah activity is performed when the item is crocheted. It might be makeh bepatish, which can be explained as completing the final stages, or boneh, building.

By the way, meisach can also be performed without having any loom at all.

Oseh batei nirin
One of the 39 melachos is oseh batei nirin, which I will not translate, but rather, explain. When weaving with a loom, one needs to have a method whereby one raises some of the warp threads while keeping the other threads depressed. This creates what is called a shed through which one inserts the woof thread, thus weaving the material. The heddle is the name of the implement used to raise and lower the warp threads, and this is done by placing the warp threads through the eyes or loops of the heddle. (There are several excellent works that have pictures to explain this process. Among them are the Artscroll, Shabbos Chapter 13, and Ma’aseh Oreg by Dayan Yisroel Gukovitzki.)

Among the halachic authorities, we find three primary opinions defining oseh batei nirin. According to some opinions, creating these loops is the melachah of oseh batei nirin (Tosafos Rid, Shabbos 73b; Gra in Shenos Eliyahu; Lechem Misheh, Hilchos Shabbos 9:16; Tiferes Yisrael, Shabbos 7:18). A different opinion contends that placing the warp threads in the loops is the melachah (Rashi, Shabbos 73a). Yet a third opinion contends that oseh batei nirin is not a stage in weaving cloth, but rather it is a type of hand-weaving process in which the final product is like a netting, mesh or basket weave. According to this approach, the melachah of oseh batei nirin has nothing to do with using a loom.

Potzei’a
The last of the five melachos that we will study in this article is potzei’a. Potzei’a is unusual in that there is no Gemara that explains what the melachah is. I have seen four different opinions among the rishonim to define the melachah.

In the Rambam’s opinion, the melachah of potzei’a constitutes undoing the weave of cloth that has already been woven, for the purpose of forming one larger piece. There are two ways to combine smaller pieces of fabric. The more common way is to sew together their edges. Indeed, this involves a melachah, but not potzei’a. Sewing two items together is the melachah of tofeir, sewing. Potzei’a is involved when someone does not want to sew the edges of the cloth together, but instead wants to blend the weave together. This is done by undoing the weave at the edge of each of the two pieces of fabric and then reweaving them together so that they form one new, larger piece of fabric. In the Rambam’s opinion, doing this involves two different melachah activities. Undoing the weave is the malachah of potzei’a, and then, reweaving it is the melachah of oreig, weaving. In his opinion, potzei’a is the opposite of weaving, similar to the way building and razing (soseir) or kindling (mav’ir) and extinguishing (mechabeh) are opposite melachos.

A second opinion is that of the Ra’avad, who contends that potzei’a is the removal or disconnection of newly woven fabric from the loom. He feels that removing threads from the weave is not potzei’a but is included under the melachah of korei’a, tearing. Just as tearing something sewn together is korei’a, so is removing threads from the weave (Ra’avad, Hilchos Shabbos 9:20; Shenos Eliyahu, Shabbos chapter 7).

A third opinion, that of Rashi (Shabbos 73a s.v. Hapotzei’a), is that potzei’a is thinning a thread that has been already spun but is thicker than one needs to weave. The melachah is removing some of the fiber from the thread. One would violate this melachah min haTorah if one thins the thread to facilitate using it for weaving.

A fourth opinion is that potzei’a is untwisting the end of a thread, so that one can now combine two threads together, end-to-end. This involves undoing the tight spinning on the ends of two threads, and then spinning them together, so that they now form one long thread (Re’ah, quoted by Ran and Ritva, Shabbos 73a). According to this opinion, potzei’a, the first step, is the opposite of the melachah of toveh, spinning thread; the second step, twisting the ends of the two threads together so that they form one thread, is toveh.

In conclusion
Rav Samson Raphael Hirsch (Shemos 20:10) notes that people mistakenly think that work is prohibited on Shabbos, in order for it to be a day of rest. He points out that the Torah does not prohibit doing avodah, which connotes hard work, but melachah, activities or actions which bring purpose and accomplishment. Shabbos is a day that we refrain from constructing and altering the world for our own purposes. The goal of Shabbos is to allow Hashem’s rule to be the focus of creation, by refraining from our own creative acts (Shemos 20:11).

This Shiur is published also at Rabbi Kaganof's site