Ohalos 8:1-2

Ohalos 8:1

Some things both convey and block ritual impurity; some things convey impurity but don’t block it, while others block impurity but don’t convey it. Some things neither convey nor block impurity. The following things both convey and block impurity: a chest, a box, a cupboard, a beehive of straw or of reeds, and the reservoir of an Alexandrian ship, so long as these things have bottoms and can hold 40 forty seah of liquid, which is two kor dry (about 140 gallons). Other things in this category include a curtain, a leather apron, a leather bedspread, a sheet, a mat and matting when these things are made into tents. Also, a herd of kosher or non-kosher domesticated animals, nests of wild animals or birds, a resting bird, a place that a woman makes for her child among the sheaves; iris, ivy, donkey vegetables, Greek gourds and ritually-clean foods. Rabbi Yochanan ben Nuri disagreed about ritually-clean foods except for a cake of dried figs.

Ohalos 8:2

Continuing the list from the previous mishna: projections (from a wall), balconies, dovecotes, crevices and caves, grottoes, cliffs, overhangs and roughness so long as they can hold a thin plaster; this is the opinion of Rabbi Meir. The Sages say they must be able to hold a normal amount of plaster. “Overhangs” refers to a tree that casts shade on the ground. “Roughness” refers to stones that project from a fence.