Tevul Yom, Chapter Two, Mishnah Eight
Today’s mishnah discusses a jug that has a bubble in the clay on the side. The bubble is pierced such that there is a passageway from the inside of the jar to the outside. The question is whether or not impurity can come from the outside and get in.
1) A bubble on a jug which was pierced with holes on its inner side and on its outer side, whether above or below:
2) If [the holes are] opposite one another, it becomes unclean [if touched] by a “father of uncleanness” and it becomes unclean if it is in a tent in which there is a corpse.
3) If the inner hole is below and the outer above, it becomes unclean [if touched] by a “father of uncleanness,” and it becomes unclean in a tent in which there is a corpse.
4) If the inner hole is above and the outer below, it remains clean if touched by a “father of uncleanness,” but it becomes unclean in a tent in which there is a corpse.
Section one: This section describes the scenario.
Section two: If the two holes are opposite one another, then the entire contents are susceptible to impurity. If a “father of uncleanness” touches the liquids at the hole, then the entire contents of the jug are impure. And if the jug is found in a tent in which there is a corpse, the contents are unclean even if the jug is tightly sealed up top. Since there is an opening, the jug is considered to be open and not protected from impurity.
Section three: The same is true if the inner hole is below and the outer hole is above. This is because the liquid the father of uncleanness touches on the outside would go down and defile all of the liquid on the inside.
Section four: However, if the inner hole is above and the outer hole is below, the liquid he touches will not go up and defile the inner liquid. Therefore, the contents remain pure.
But in all cases since the jug is open through both sides, the contents are defiled by being in a tent with a corpse.