Shabbat 31

לא ליטמו מגבן אלמה תנן. כלי חרס וכלי נתר טומאתן שוה מיטמאין ומטמאין מאויריהן ומיטמאין מאחוריהן ואין מיטמאין מגביהן ושבירתן מטהרתן כלי נתר וכלי חרס הוא דטומאתן שוה אבל מידי אחרינא לא אמרי כיון. דכי נשתברו יש להם תקנה שוינהו ככלי מתכות

let them not become unclean through their [flat or convex] backs.<span class="x" onmousemove="('comment',' If an unclean object touches them on the back, which is flat or convex, they should not become unclean, in accordance with the Mishnah quoted. ');">¹</span> Why did we learn, Earthen vessels and nether vessels<span class="x" onmousemove="('comment',' Rashi: a kind of white earth; Jast.: a vessel made of alum crystals. ');">²</span> are alike in regard to their uncleanness: they become defiled and defile [other objects] through their air space;<span class="x" onmousemove="('comment',' If an unclean object is suspended in the hollow of one of these vessels, even if it does not touch its side, it becomes unclean. Again, if a clean object is suspended in the hollow of an unclean vessel, though it does not actually touch it, it too becomes unclean. ');">³</span>

אלא מעתה יחזרו לטומאתן ישנה ככלי מתכות דתנן כלי מתכות פשוטיהן ומקבליהן טמאין נשברו טהרו חזר ועשה מהן כלים חזרו לטומאתן ישנה ואילו גבי כלי זכוכית תנן כלי עץ וכלי עור וכלי עצם וכלי זכוכית פשוטיהן טהורין ומקבליהן טמאין נשברו טהרו חזר ועשה מהן כלים מקבלין טומאה מכאן ולהבא מכאן ולהבא אין למפרע לא

they become unclean through their outside,<span class="x" onmousemove="('comment',' E.g., if the base is concave, and an unclean object is suspended from the outside in the hollow. ');">⁴</span> but they cannot be defiled through their backs;<span class="x" onmousemove="('comment',' Which are flat or convex. ');">⁵</span> and their breaking renders them clean.<span class="x" onmousemove="('comment',' If these vessels, being already unclean, are broken, they become clean; cf. p. 65, n. 7. ');">⁶</span>

טומאת כלי זכוכית דרבנן וטומאה ישנה דרבנן בטומאה דאורייתא אחיתו בה רבנן טומאה בטומאה דרבנן לא אחיתו לה רבנן טומאה

Thus, only earthen and nether vessels are alike in regard to their uncleanness, but not other things?<span class="x" onmousemove="('comment',' yet glass vessels too should be the same according to Resh Lakish's reason. ');">⁷</span> — I will tell you: since they can be repaired when broken,<span class="x" onmousemove="('comment',' By being melted down and refashioned, which is impossible with earthen utensils. ');">⁸</span> they were assimilated to metal utensils.<span class="x" onmousemove="('comment',' Which can be repaired in the same way. ');">⁹</span>

פשוטיהן מיהא ליטמא דהא פשוטי כלי מתכות דאורייתא נינהו עבדי בהו רבנן הכירא כי היכי דלא לשרוף עלייהו תרומה וקדשים

If so, let them revert to their former uncleanness, like metal utensils? For we learnt: Metal vessels, both flat and hollow,<span class="x" onmousemove="('comment',' Lit., 'those of them which receive'. ');">¹⁰</span> are subject to defilement. If broken, they become clean; if remade into utensils, they revert to their former uncleanness. Whereas in respect to glass vessels we learnt: Wooden, skin, bone and glass utensils, if flat, they are clean;<span class="x" onmousemove="('comment',' I.e., they cannot be defiled. ');">¹¹</span> if hollow, they are unclean;<span class="x" onmousemove="('comment',' As in n. 7. ');">¹²</span> if broken, they become clean; if remade into vessels, they are liable to defilement from then onwards. [Thus] only from then onwards, but not retrospectively? — The uncleanness of glass utensils is Rabbinical, and [the resuscitation of] former uncleanness is [also] Rabbinical: now, in the case of that which is unclean by Scriptural law, the Rabbis have imposed [retrospective] uncleanness upon it, but upon that which is unclean by Rabbinical law the Rabbis have imposed no [retrospective] uncleanness. Yet at least let their flat utensils be unclean, since flat metal utensils are [susceptible to uncleanness] by Scriptural law!-The Rabbis made a distinction in their case, so that <i>terumah</i> and sacred food should not be burnt on their account.<span class="x" onmousemove="('comment',' For these must not be burnt when defiled by Rabbinical law, except in the six cases of doubtful uncleanness enumerated on 15b. ');">¹³</span>