Uktzin, Chapter 2, Mishnah 1. The mesechta is devoted to the parts of a food that are not eaten: the stems, stalks and pods attached to fruits and vegetables. Such a part may be a yad, a handle, in which case it receives tumah along with the food and transmits tumah to it, and it may also be a shomer, a protector of the food, in which case it even joins together with the food to complete the measure of tumah. Our mishnah lists which stems fall into each category.
"Uktzei te'einim vehagrogros vehaklusin vehecharuvin, harei eilu mitam'in umitam'in umitztarfin". An uketz means the short woody stalk that juts out of a fruit. Listed here are the stalks of fresh figs; of grogros, figs that have been dried; of klusin, a strain of fig of far greater sweetness; and of carobs, where a person holds on to the slim piece of wood extending from the bokser while he eats it. Every one of these carries the status of a yad. The result works in both directions: tumah that reaches the stalk passes into the fruit, and a fruit that has contracted tumah renders its stalk tamei as well. There is a further point, taught by the word "umitztarfin": a stalk of this sort has the din of a shomer too, so its bulk is added to that of the fruit in measuring the shiur for tumah. What lies behind this? Detach that thin stem and the fruit will begin to rot sooner, and whatever guards food from spoiling qualifies as a protector.
Rabbi Yehudah wishes to place one more item on this list, "af uketz deluas", the stalk of a gourd, which in his view serves both as a handle and as a protector.
"Uktzei ha'agasin vehakrustemalin vehaprishin veha'uzradin": a second list follows, made up of the stalks of pears, of krustemalin, pears of a smaller sort, of prishin, identified as the quince, and of uzradin, explained by some to be crab apples. Two further items come with a limit attached: "uketz deluas tefach, uketz kunras tefach", the stalk of a gourd and the stalk of a kunras (generally taken to be the artichoke), each of which qualifies as a handle for as much as a tefach, about four inches, of its length. Rabbi Elazar the son of Rabbi Tzadok holds that the allowance extends to "tefachayim", double that measure.
"Harei eilu mitam'in umitam'in velo mitztarfin": this second group receives tumah and conveys tumah to the fruit and from it, exactly like the first group, but with one difference: they do not join together with the food. They are not counted toward the shiur of a kabeitzah, because although they serve as handles they are not protectors of the fruit.
"Ush'ar kol ha'uktzin lo mitam'in velo mitam'in": every other stem, that is, all the stems protruding from fruits and vegetables that were not enumerated here, is not regarded as a handle at all. Such a stem neither receives tumah nor conveys it, and needless to say it is not a protector either, so it does not join with the food to complete the measure of tumah that would enable the food to render something else tamei.
The mishnah has thus set out three levels: a stem that is both handle and protector, a stem that is a handle alone, and a stem that is neither. Everything turns on how a person actually relates to that little piece of wood: whether he grips it when he takes the fruit, and whether the fruit needs it in order to keep.