Just as they curtail [tumah] when they are inside, so do they curtail [tumah] when they are outside. How so? An olive-pressing basket is placed on pegs outside [a house. If] there is tumah underneath the olive-pressing basket, utensils inside it re-main tahor. If [the olive-pressing basket is placed on pegs next to] the wall of a courtyard or the wall of a garden, it does not curtail [tumah]. A beam is placed between two walls, and a pot is suspended from [the beam]. [If] there is tumah beneath [the beam], utensils inside the pot are ruled tahor by R’ Akiva, but they are ruled tamei by the Sages.

Man and utensils become roofs to convey tumah, but not to maintain something as tahor. How so? Four [people] are holding a slab of stone. [If there] is tumah below [the slab], the utensils on top of it become tamei. [If] there is tumah above it, the utensils underneath it become tamei. R’ Eliezer declares [them] tahor. [The slab] is placed on four utensils, even utensils made of dung, stone, or unbaked clay. [If] there is tumah underneath it, utensils on top of it become tamei. [If] there is tumah above it, the utensils underneath it become tamei. [The slab] is placed on four stones or on a living creature. [If] there is tumah underneath [the slab], the utensils on top of it remain tahor. [If] there is tumah above it, the utensils underneath it remain tahor.