Before I begin to discuss Kelim, I would like to begin with a note on learning the laws of purity, a subject which we have only indirectly touched upon until now. The very fact that at least 1/6 of the Mishnah and probably a large percentage of Leviticus are dedicated to the laws of purity certainly implies that these rules had important meaning in their lives. For us it is hard to determine what exactly that meaning might have been, but my sense is that all societies, primitive and modern, have their ways of ordering the world, and that purity/impurity systems are a means of going about this. This is a subject that Mary Douglass, an anthropologist, has written extensively about (she even has a book on Leviticus). I would urge any of you who are interested in further reading to look at some of her work, or the commentaries of Jacob Millgrom, for further insights into some of these subjects. Jonathan Klawans has also written an excellent book on purity. While nearly all of these rules are no longer practiced, I think that if we want to truly enter into the rabbinic bet midrash, into their way of thinking, there is no better way to do so than to learn Seder Toharot. There are five main causes of impurity discussed in Seder Toharot: 1) A dead body. 2) The eight creepy-crawly things listed in Leviticus 11. These are called "sheretz/sheratzim." 3) The carcass of a nevelah, a kosher animal that was not slaughtered properly. 4) The zav or zavah (man or woman suffering abnormal genital discharge), a menstruant or a woman who gave birth. 5) Tsaraat, which is some sort of skin disease. These five sources of impurity are discussed in the first chapter of Kelim.
The following items can become impure: people, vessels, food and drinks. To become susceptible to impurity, food must first come into contact with a liquid. People and vessels can become pure by entering a mikveh. After entering the mikveh they become pure after sunset. A person who becomes impure through contact with a dead body must undergo a stricter purification process, involving the ashes of the red heifer. There are obviously many more rules that we will learn on the way, but these are the basics, and if you remember them, you will find the Seder a bit easier (just a bit!).
The word "kelim" means "vessels" but it has a broader meaning in mishnaic Hebrew than the word "vessels" in English. It basically includes most things made for human use—utensils, tools, clothing, furniture and many others. Our tractate deals with how these objects can become impure and pure, and how they convey purity to other things, mostly food and drink. At the outset, I will describe certain rules that the rabbis established. Most of these were learned either directly or indirectly from biblical verses, but I shall not go in to all of the midrashim that lie at the heart of these rules. The verses are found below, and we shall make frequent reference to them throughout.
How a vessel receives/conveys impurity depends largely on the material from which that vessel was made. We shall now deal with the materials addressed throughout the tractate.
Earthenware: Earthenware vessels become impure only if something impure falls into them. They cannot become impure by something touching their outside. However, from the inside they can become impure even without contact, for instance the impure thing hangs inside their air space. Because of this rule, for an earthenware vessel to become impure it must have an inside, such as a cup, a tub, a jar, etc. If the earthenware vessel has a lid and the lid is sealed to it, impurity cannot enter. Earthenware vessels convey impurity to food and drink found inside, even if they are not touching. But they do not convey impurity to other vessels.
Other types of vessels (especially wood, leather and bone): Vessels made of other types of material receive impurity by contact, even if they don't have any inside. However, if impurity enters their airspace, they are not impure. Wooden, leather and bone vessels must be meant to receive or hold both people and things in order to become impure. For instance, a wooden table can become impure, because it serves both people and things, but a ladder only serves people and therefore it cannot become impure. They most also be the types of vessels that are moved for them to become impure. Thus a very large container cannot become impure. They convey impurity to food and drink. Vessels made of stone, dirt or manure cannot become or convey impurity. According to Torah law, glass vessels also cannot become or convey impurity. However, rabbinic law treats them as wood, leather and bone vessels.
The major difficulty in understanding Kelim is that we often don't have a clear picture as to what the vessel being discussed actually was. The words for vessels tend to change over time, as technology and language develop, and rabbinic traditions did not always preserve what the meaning of these words was. In addition, Kelim and all of Seder Toharot was not as well learned as other sedarim and tractates, again contributing to a loss in meaning. As is typical in the Mishnah, the mishnah often conveys its meaning by using specific examples, as opposed to outlining general rules. The problem is that when one doesn't understand the example, the rule is harder to understand. We will do the best we can in learning this tractate, and as a rule, I shall use Albeck's explanations. In order to prevent confusion, I will infrequently cite variant explanations. I hope that despite these difficulties, the tractate is interesting and somewhat intelligible.
Leviticus 11 29 The following shall be unclean for you from among the things that swarm on the earth: the mole, the mouse, and great lizards of every variety; 30 the gecko, the land crocodile, the lizard, the sand lizard, and the chameleon. 31 Those are for you the unclean among all the swarming things; whoever touches them when they are dead shall be unclean until evening. 32 And anything on which one of them falls when dead shall be unclean: be it any article of wood, or a cloth, or a skin, or a sack — any such article that can be put to use shall be dipped in water, and it shall remain unclean until evening; then it shall be clean. 33 And if any of those falls into an earthen vessel, everything inside it shall be unclean and [the vessel] itself you shall break. 34 As to any food that may be eaten, it shall become unclean if it came in contact with water; as to any liquid that may be drunk, it shall become unclean if it was inside any vessel. 35 Everything on which the carcass of any of them falls shall be unclean: an oven or stove shall be smashed. They are unclean and unclean they shall remain for you. 36 However, a spring or cistern in which water is collected shall be clean, but whoever touches such a carcass in it shall be unclean. 37 If such a carcass falls upon seed grain that is to be sown, it is clean; 38 but if water is put on the seed and any part of a carcass falls upon it, it shall be unclean for you.
Leviticus Chapter 15 1 The Lord spoke to Moses and Aaron, saying: 2 Speak to the Israelite people and say to them: When any man has a discharge issuing from his member, he is unclean. 3 The uncleanness from his discharge shall mean the following — whether his member runs with the discharge or is stopped up so that there is no discharge, his uncleanness means this: 4 Any bedding on which the one with the discharge lies shall be unclean, and every object on which he sits shall be unclean. 5 Anyone who touches his bedding shall wash his clothes, bathe in water, and remain unclean until evening. 6 Whoever sits on an object on which the one with the discharge has sat shall wash his clothes, bathe in water, and remain unclean until evening. 7 Whoever touches the body of the one with the discharge shall wash his clothes, bathe in water, and remain unclean until evening. 8 If one with a discharge spits on one who is clean, the latter shall wash his clothes, bathe in water, and remain unclean until evening. 9 Any means for riding that one with a discharge has mounted shall be unclean; 10 whoever touches anything that was under him shall be unclean until evening; and whoever carries such things shall wash his clothes, bathe in water, and remain unclean until evening. 11 If one with a discharge, without having rinsed his hands in water, touches another person, that person shall wash his clothes, bathe in water, and remain unclean until evening. 12 An earthen vessel that one with a discharge touches shall be broken; and any wooden implement shall be rinsed with water. 19 When a woman has a discharge, her discharge being blood from her body, she shall remain in her impurity seven days; whoever touches her shall be unclean until evening. 20 Anything that she lies on during her impurity shall be unclean; and anything that she sits on shall be unclean. 21 Anyone who touches her bedding shall wash his clothes, bathe in water, and remain unclean until evening; 22 and anyone who touches any object on which she has sat shall wash his clothes, bathe in water, and remain unclean until evening. 23 Be it the bedding or be it the object on which she has sat, on touching it he shall be unclean until evening. 24 And if a man lies with her, her impurity is communicated to him; he shall be unclean seven days, and any bedding on which he lies shall become unclean. 25 When a woman has had a discharge of blood for many days, not at the time of her impurity, or when she has a discharge beyond her period of impurity, she shall be unclean, as though at the time of her impurity, as long as her discharge lasts. 26 Any bedding on which she lies while her discharge lasts shall be for her like bedding during her impurity; and any object on which she sits shall become unclean, as it does during her impurity: 27 whoever touches them shall be unclean; he shall wash his clothes, bathe in water, and remain unclean until evening.
Numbers 19 14 This is the ritual: When a person dies in a tent, whoever enters the tent and whoever is in the tent shall be unclean seven days; 15 and every open vessel, with no lid fastened down, shall be unclean.