מסכת כלים

פרק כד משנה יז

שלש קפות הן

There are three types of boxes:

מהוהה

A worn one (that is still intact and functional)

that was attached to a sound one (one box was placed inside the other, and then the two were glued or nailed together, forming a single, reinforced box)

we follow the whole one (in determining the tumah/taharah status of this new composition; thus, if the worn box had been tamei when attached and the sound one was tahor, the newly created combined box will be tahor);

if a small one was on a large one,

we follow the large one;

if they were equal,

we follow the interior one.

Rabbi Shimon says,

the pan of a balance scale (which was tamei, and made of metal)

that was attached to the bottom of a (tahor) boiler (thus reinforcing the floor of this utensil),

(if the pan was attached) from inside (the boiler)

(the boiler) is tamei,

from outside

it (including the pan) is tahor,

if it was attached to the side

whether from inside or outside

is tahor.

כל הכלים

All utensils

have an exterior and an interior (these surfaces have different rules; for example, if a tamei liquid comes into contact only with the exterior, the exterior is rabbinically tamei while the interior remains tahor, but if it touches only the interior, the entire vessel, including its exterior, is rabbinically tamei),

such as pillows,

and mattresses,

and sacks,

and martzufim (large leather sacks used to transport goods on ships),

these are the words of Rabbi Yehuda;

Rabbi Meir says,

any that has loops (these were used for drawstrings that would close the aforementioned utensils, and would give the bag a distinct interior and exterior)

have an exterior and an interior,

that which do not have a loop (and so can be turned inside out)

do not have a exterior and an interior (and both surfaces are treated as the interior).

השולחן

The table

and the delphica

have an exterior and interior (their finished surfaces are deemed their "interior", and their unfinished undersides are considered as their "exterior"),

these are the words of Rabbi Yehuda;

Rabbi Meir says,

they do not have exteriors;

and similarly a tray that has no rim (there is the same difference of opinion with regard to the unfinished underside of such a utensil).