Keilim 3:7-8

Keilim 3:7

Regarding an earthenware kettle that was coated with cement or clay, food or liquids that touch the cement are susceptible to ritual impurity (because the cement is considered permanently affixed) but those that touch the clay are not (because the clay is considered temporarily affixed). If an urn was purified by piercing it and then repaired by sealing it with tar, Rabbi Yosi says that it is not susceptible to ritual impurity because it can no longer hold hot water the way it does cold. He said the same thing about other utensils that are coated with tar. Therefore, copper vessels coated with tar are not susceptible to ritual impurity but if they are intended for wine (which is served cold), then they are susceptible.

Keilim 3:8

Let’s say that a jar was purified by piercing it and then repaired with an excessive amount of tar. Any food or liquid that touches the necessary tar is susceptible to ritual impurity, while that which touches the excess tar is not. If tar dripped onto a jar, food or drink that touches it is not susceptible to ritual impurity. If one were to plug up a wooden or earthenware funnel with tar (forming a receptacle), Rabbi Elazar ben Azarya says that it is susceptible to ritual impurity (as a proper vessel). Rabbi Akiva says that the wooden funnel is susceptible to ritual impurity but the earthenware funnel isn’t (because the plug will likely be removed. This is not the case with the wooden funnels because tar was made from tree resin and considered part of them). Rabbi Yosi says that neither kind of funnel is susceptible to ritual impurity (because of the likelihood that the plug will be removed).