Shabbat 16a (טז.) — the Talmud in English

And furthermore we ask: Since they made glass vessels equivalent to earthenware vessels,

if so,

should they not become impure through impurity that touches

their

backs

[on their outer sides], as is the law with earthenware vessels, which become impure only if the impurity enters their interior?

Why,

then, do we not uphold this?

As we learned: Earthenware vessels and vessels of natron

[whose manner of manufacture is like that of earthenware vessels, except that they are made from a type of white earth]—

their impurity is equal

to one another.

Both

become impure

[receive impurity],

and

both

render

others impure

through their airspace.

For even if the impurity—for example, a creeping creature—does not touch their walls, but is suspended within the space of their airspace, they are impure.

And similarly, once earthenware vessels and vessels of natron have become impure, if food is suspended within their airspace, the food becomes impure through them, even though it did not touch their walls. As it is written: “Whatever of them falls into its interior.” This law was introduced only with regard to earthenware vessels and vessels of natron. Other vessels, however, neither become impure nor render others impure except through contact with their walls.

And

they are likewise equivalent in that

they become impure through their backs.

If impurity enters the hollow of their backs [which is hollowed out for them below, in the place where they rest], they become impure. Their backs are considered like their interior because they possess a receptacle . And certainly, they render others impure through their backs [ Tosafot] .

However,

they do not

become

impure through their outer sides!

As is derived in Chullin 25a from an earthenware vessel sealed with a tightly fitted cover, which does not become impure in a tent containing a corpse. This is because it becomes impure only through its interior. Since the cover separates its interior from the impurity of the corpse, it does not become impure, even though its back is exposed to impurity.

This requirement applies specifically to receiving impurity: an earthenware vessel must receive the impurity through its interior. But once an earthenware vessel has become impure through its interior, it renders others impure even if they touch its back.

And

they are likewise equivalent in that neither of them can be purified in a mikveh, but

their breaking

alone

purifies them!

And we conclude the objection: It follows that specifically

vessels of natron and earthenware vessels have equal impurity

in that they do not become impure through their backs.

But something else

such as glass vessels

does not

share this feature with earthenware vessels. Rather, it receives impurity even through its back. This is difficult for Rabbi Yoḥanan and Reish Lakish, who say: “The Sages made them equivalent to earthenware vessels”!

And we answer:

They said: Since

they also resemble metal vessels,

for

when these

break, they can be repaired

like metal vessels, by melting them and making vessels from them again [unlike earthenware vessels, from which it is impossible to make vessels again] —

they also made them equivalent

the Sages

to

metal

vessels, so that they render impure through their backs.

And we ask again:

If so,

if the law of metal-vessel impurity also applies to them—if they became impure and then broke, and their impurity departed, and afterward they were repaired—

should they return to their

old

impurity

like metal vessels?

As we learned: Metal vessels—

their flat ones

[which do not have a receptacle]

and their receptacles

[which do have a receptacle]

are impure.

And if

they break, they become pure

from their impurity, since the status of a vessel no longer applies to them.

And if, after they became impure and broke,

he again made vessels from them—

they return to their

old

impurity.

And later it explains the reason.

Whereas

with regard to

glass vessels,

we do not uphold this.

For

we learned: Wooden vessels, leather vessels, bone vessels, and glass vessels—

their flat ones are pure, but their receptacles are impure.

For wooden vessels and leather vessels are compared to a sack, as it is written: “Of any wooden vessel or garment or leather or sack.” Just as a sack can be carried both full and empty [because it has a receptacle], so too, every vessel among all these types receives impurity only when it can be carried both full and empty.

Bone vessels are compared to wood and leather, as it is written: “Every garment and every leather vessel and every goats’ product and every wooden vessel.” And we expound from the phrase “every goats’ product”: Anything derived from goats, including vessels made from horns, bones, and hooves. Therefore, all of them become impure only when they have a receptacle. The reason for the law of glass vessels is explained below.

And if

they break, they become pure

because the status of a vessel no longer applies to them.

And if

he again made vessels from them—

they

receive impurity,

if they come into contact with impurity

from that point onward.

And we conclude the objection: It follows that specifically

from that point onward, not

do they receive impurity. But

retroactively, no:

their old impurity does not return to them.

This is difficult: They were made equivalent to metal vessels, so what is the difference between glass vessels and metal vessels?

And we answer:

The impurity of glass vessels

is, in its entirety, only

rabbinic.

And

the return of

old impurity

is also only

rabbinic.

But specifically with regard to metal vessels and the like, which became impure

with Torah impurity

before they broke,

the Sages imposed upon it

they restored to it

the Sages the old

impurity

of Torah origin after they broke and he again made them into a vessel.

But glass vessels, which by Torah law have no capacity whatsoever to receive impurity, and which even initially, before they broke, became impure only

with

rabbinic impurity,

the Sages did not impose upon it

again the old

impurity

after they broke and he again made them into a vessel.

And we ask again: The

flat ones

of glass vessels,

at least, should become impure

like metal vessels!?

Here you cannot answer as we answered above with regard to old impurity.

For the flat ones of metal vessels

are,

by Torah law,

fit to receive impurity;

they are.

And since the Sages made glass vessels equivalent to metal vessels, all the laws of impurity that apply to metal by Torah law should be included in this decree!?

And we answer: Since the impurity of glass vessels is rabbinic, and one does not burn teruma and consecrated offerings on account of rabbinic impurity [except for the six uncertainties that we learned above] —

the Sages made a distinction for them,

between them and Torah impurity, by ensuring that they do not become impure through their flat ones.

So that

one will recognize through them that they are not impure by Torah law, and

will not

come

to burn teruma and consecrated offerings because of them .