Kelim, Chapter Two, Mishnah Seven
Our Mishnah deals with some vessels that have multiple parts. The main issue at hand is whether all parts become unclean if one part does.
The following among earthen vessels are susceptible to impurity:
1) A tray with a rim,
2) An unbroken fire-pan,
3) And a tray made up of dishes,
a) If one of them was defiled by a [dead] creeping thing they do not all become unclean,
b) But if it had a rim that projected above the rims of the dishes and one of them was defiled all are unclean.
4) Similarly with an earthen spice-box and a double ink-pot.
a) If one container was defiled from a liquid, the other is not unclean.
b) Rabbi Yohanan ben Nuri says: its thickness is divided and that side which serves the unclean one is unclean while that which serves the clean one remains clean.
c) If its rim projects above the others and one of them contracted impurity the other is unclean.
Section one: This is the opposite of the tray mentioned in Mishnah three, which did not have a rim.
Section two: Also referred to in mishnah three.
Section three: The mishnah refers to a tray that has dishes attached to it. If one dish is defiled, the others remain pure. However, if the tray has a rim above it that surrounds all of the dishes, it joins them into one vessel. In such a case if one dish is defiled, all are unclean.
Section four: These two vessels also have multiple parts, such that if one is defiled the other is not. For instance if the liquid in one side becomes impure by contact with a sheretz, the liquid only touches the outside wall of the other side of the vessel and vessels are not defiled by having their outsides defiled by a liquid. However, if the sheretz had touched the vessel itself, one side of the wooden vessel will convey its impurity to the other side. This is a subject to which we return later in the tractate.
Rabbi Yochanan ben Nuri says that the wall that separates the two sides can be divided in two. The side that was on the impure half is impure, whereas the side on the half that didn’t come into direct contact with the liquid remains clean.
Finally, as in the previous case, if there is a rim that projects above and around both sides, it serves to join the two separate halves into one vessel, meaning that all sides are defiled.