Kelim, Chapter Eight, Mishnah One
1) An oven which they partitioned with boards or hangings, and in it was found a sheretz in one compartment, the entire oven is unclean.
2) A hive which was broken and its gap was stopped up with straw and was suspended within the air-space of an oven while a sheretz was within it, the oven becomes unclean.
3) If a sheretz was within the oven, any food within the hive becomes unclean.
a) But Rabbi Eliezer says that it is clean.
4) Rabbi Eliezer said: if it affords protection in the case of a corpse which is more consequential, should it not afford protection in the case of an earthenware vessel which is less consequential?
5) They said to him: if it affords protection in the case of corpse impurity, this is because tents are divided, should it also afford protection in the case of an earthenware vessel which is not divided?
Section one: If people divided an oven into different parts, all the way from the bottom to the top, and then a dead sheretz (an impure creepy crawling thing) is found in one section, the entire oven is impure. This is because a partition put into an earthenware vessel does not count as far as stopping impurity from spreading from one side to the other.
Section two: The mishnah now complicates the picture a bit more. If a vessel shaped as a beehive was broken, it no longer counts a vessel, even if the gap was stopped up with straw. If there is a sheretz in this vessel and the entire vessel is suspended in an oven, the impurity breaks out of the hive-vessel and defiles the oven.
Section three: Similarly, at least according to the sages, if there is a sheretz within the oven, the impurity of the sheretz defiles that which is in the hive-vessel.
Rabbi Eliezer disputes and holds that the hive which has been stopped up with straw protects the food within it from being contaminated by the sheretz in the oven.
Section four: Rabbi Eliezer argues his point by making an analogy with a corpse found in a building. If a corpse is in a building and the building has been divided by boards or curtains, the vessels found in sections of the building in which the corpse is not present are not considered contaminated. If, Rabbi Eliezer reasons, partitions protect against corpse impurity which is the most serious form of impurity, then the partition of the hive should also protect the food within it. In other words, even if the vessel is not complete, it should still count as a partition, just as do curtains and boards in a building.
Section five: The other rabbis reject his argument because the situations are not analogous. Tents, i.e. buildings, are commonly partitioned, and therefore their partition succeeds in dividing one section from the other. In contrast, as we learned in the first half of the mishnah, partitions within ovens are not typical and therefore they do not succeed in stopping the impurity from going to the other side.
Here is a classic example where we can see that the laws of impurity are not purely physical but that they in some way describe reality. The material that is used to divide an oven or a house may be the exact same thing, but in one case it provides a barrier to the spread of impurity and in the other case it does not. The law conveys the reality that houses are divided into parts and ovens are not.