Keilim 2:1-2

Keilim 2:1

Utensils of wood, leather, bone and glass that do not have a receptacle are not susceptible to ritual impurity; those that have a receptacle are susceptible and, if they are broken, they return to a state of ritual purity. If one remade the pieces back into utensils, they are susceptible to impurity from that point on (but they do not reacquire their previous impurity). Earthenware utensils and those made of neser (natron, a mineral, which is similar to earthenware) are the same in matters of impurity: they contract and transmit ritual impurity through their interior airspace, they transmit impurity through their outside but they do not contract impurity through their outsides, and breaking them renders them ritually clean.

Keilim 2:2

Regarding the smallest earthenware vessels, as well as the bottoms and sides of broken large earthenware vessels that can stand unsupported, the minimum size that is susceptible to ritual impurity is sufficient to hold enough oil to anoint a newborn’s pinky – this is for vessels that were originally up to a log in volume before being broken. If the original vessel was from a log to a seah, it must now be able to hold a reviis*. If it was originally from a seah to two seah, it must now be able to hold half a log*. From an original size two seah to three or even five seah, it must now hold a log*; this is the opinion of Rabbi Yishmael. Rabbi Akiva doesn’t base his rulings on the size of the unbroken vessels. Rather, regarding the smallest earthenware vessels, as well as the bottoms and sides of broken large earthenware vessels that can stand unsupported, the minimum size that is susceptible to ritual impurity is sufficient to hold enough oil to anoint a newborn’s pinky. This is for vessels that were originally no bigger than the small cooking pots. For vessels that were originally from the size of small cooking pots up to the size of jugs from Lydda, they must now be able to hold a reviis. For vessels that were originally from the size of Lydda jugs to that of Bethlehem jugs, they must now be able to hold half a log. For vessels that were originally from the size of Bethlehem jugs to that of large urns, they must now be able to hold a log. Rabbi Yochanan ben Zakkai says broken large urns must now be able to hold two logs; the minimum size for broken Galilee jars and miniature jugs is any part of their bottom at all but they had no sides (i.e., they were conical so their receptacle was “all bottom”).

*A reviis (i.e., a quarter of a log) is about 3.3 fluid ounces. Pursuant to this, half a log is around 6.5 ounces and a log is around 13 ounces.