Keilim, Chapter 15, Mishnah 1. The chapters that follow deal with vessels made of wood and of leather, and this mishnah lays the foundation for all of them. Before entering the many detailed halachot ahead, the Mishnah sets down the basic rules that govern when such vessels are susceptible to tumah at all.
The mishnah begins by grouping four materials under a single heading. "Kol keli eitz" takes in whatever is fashioned out of wood; alongside it stand "keli or," items of leather, "keli etzem," items of bone, and "keli zechuchit," items of glass. For all four the law is identical: "peshuteihen tehorin," a flat item among them, one with no hollow that holds anything, is incapable of receiving tumah, "umekabeleihen temei'in," whereas one shaped so as to contain something falls under the laws of tumah and can become tamei.
Next the mishnah turns to damage: "Nishberu, taheru." Where one of these utensils had already contracted tumah and then broke apart, the tumah departs together with its standing as a utensil, and the fragments are pure. But suppose those fragments are not discarded. "Chazar ve'asa meihen keilim": the owner reworks the pieces into utensils a second time. The halachah in that case is "mekabelin tumah mikan ulehabah," susceptibility resumes from this moment on, looking forward only. The former tumah is not reinstated in them; what lies before us is a newly produced utensil, and whatever tumah it takes on from here belongs to it alone.
Six large vessels that stay tahor
Having established that any wooden vessel with a receptacle can become tamei, the Mishnah presents a list of exceptions. "Hashida" is a large wooden chest. "Hateiva" is the box of a moneychanger. "Hamigdal" is a wooden cabinet in which household articles are kept. "Kavetet hakash ve'kavetet hakanim" are an oversized basket of straw and an oversized basket of reeds. "U'vor sefina aleksandrit" is the wooden water tank of an Alexandrian ship: since seawater was undrinkable, those Egyptian vessels carried great containers of fresh water along with them for the voyage.
Two conditions define these six. "Sheyesh lahem shulayim": they have flat bottoms, so that they rest solidly on the ground and are not readily shifted from their place. "Vehein machzikin arba'im se'ah balach, shehem kora'yim bayavesh": their capacity is forty se'ah of liquid, the equivalent of two kor of dry produce. Of these the Mishnah rules "harei eilu tehorin." Although they are genuine receptacles made of wood, they remain pure and are the exception to the general rule.
The reason lies in the nature of a vessel. Wood, leather and bone become susceptible to tumah only when the object is small enough to be carried even while it is full. A container with a flat base and a capacity of forty se'ah cannot be picked up and moved once its contents are inside it, and so it never enters the category of a vessel for these purposes.
Rebbi Meir's rule
Rebbi Meir now rounds out his ruling. "U'she'ar kol hakeilim" means every wooden article other than those six, and of them he says "temei'in," they fall under the laws of tumah, and this applies "bein mekabelin," if they hold forty se'ah of liquid, "bein einan mekabelin," and equally if they do not. Articles of that kind were produced in order to be lifted and shifted about, so even a generous capacity does not release them from susceptibility. "Divrei Rebbi Meir": this is his view, that utensils of wood, leather or bone remain susceptible however far beyond forty se'ah they reach, the six he enumerated being the only items withdrawn from the rule.
Notice how Rebbi Meir framed his teaching. He named the large vessels that cannot become tamei and then declared that everything else can. Rebbi Yehuda, who follows, works from the opposite direction: he lists the large vessels that in his view are susceptible, and rules that all others are not.
Rebbi Yehuda's rule
"Rebbi Yehuda omeir": Rebbi Yehuda now sets out a list of his own. "Dardur agala" is a sizable wooden water barrel fixed onto a wagon. "Ve'kustot hamelachim" is the wooden case in which provisions for kings were stored. "Ve'areivat ha'avdanin" is the broad wooden trough in which a tanner steeps hides. "U'vor sefina ketana" refers to the freshwater cistern built into a boat of modest size. "Ve'ha'aron" is a large wooden casket for burial.
Of all five Rebbi Yehuda rules "af al pi she'mekabelin," notwithstanding that each one takes in a full forty se'ah of liquid, nonetheless "temei'in," every one of them falls under the laws of tumah. His reasoning is spelled out as well: "she'einan asuyin letaltel ela bemah shebetochan," they were produced from the start to be carried while loaded. An article whose whole purpose is to travel about with its contents inside it stands on the identical footing as any ordinary portable utensil, and susceptibility applies to it.
What, then, of the balance of wooden utensils? "U'she'ar kol hakeilim": regarding them the halachah reads "hamekabelin tehorin," one that takes in forty se'ah stays pure, since a container of such dimensions is taken to have been produced in order to stand in one spot, "veshe'einan mekabelin temei'in," while one falling short of forty se'ah is susceptible, being taken to have been produced for carrying about.
Where the two opinions actually part
The two Tannaim share one and the same yardstick: a large receptacle meant to be transported is susceptible to tumah, whereas one meant to stay in place is not. If so, what is actually at stake between them? The mishnah supplies the answer: "Ein bein divrei Rebbi Meir," nothing divides the ruling of Rebbi Meir, "ledivrei Rebbi Yehuda," from the ruling of Rebbi Yehuda, "ela areivat ba'al habayit," apart from a single case, the large kneading trough of an ordinary homeowner, one that holds forty se'ah.
That trough is absent from both lists. Rebbi Meir omitted it from his six pure utensils, so it belongs to all the others, which for him are susceptible. Rebbi Yehuda omitted it from his five susceptible utensils, and by his reckoning it consequently stays pure. The entire disagreement contracts to that one item, and it emerges from the two lists themselves: the six that Rebbi Meir placed beyond the reach of tumah together with the five that Rebbi Yehuda placed within it, eleven cases in all, marking out the limits of what the two of them are debating.