Tohoros 8:1-2

Tohoros 8:1

Let’s say that a learned person shares a courtyard with an unlearned person and the learned person left some utensils in their shared yard. Even if they were jars with tight-fitting lids or an oven with a tight-fitting cover, they are unclean. Rabbi Yehuda says that an oven with a tight-fitting cover is clean. Rabbi Yosi says that even an oven is unclean unless the owner surrounded it with a partition ten handbreadths tall (about 30”).

Tohoros 8:2

If a learned person deposited utensils with an unlearned person, they are considered unclean with corpse impurity and midras impurity. If the watchman knows that the owner eats trumah, they are clean of corpse impurity but unclean with midras impurity. Rabbi Yosi says that if he deposited a trunk of clothes with the unlearned watchman, they are ruled unclean with midras impurity if they’re tightly packed but only with madaf impurity (a lesser form of impurity) if they’re not tightly packed. This is so even if the owner is in possession of the key.