Sukkah 17a — the Talmud in English

Mishna:

The Mishna before us explains the halakha of “dofen akuma” in three different ways.

The common element in all three cases is that the walls are distant from the schach.

Wherever the walls are distant from the schach—for example, where there is airspace measuring three tefachim between the walls and the schach—the sukka is invalid.

But where the halakha of “dofen akuma” was stated, the walls are considered adjacent to the schach, as will be explained.

The Mishna begins by explaining the invalidity of walls that are distant from the schach:

If one distanced the schach from the walls

toward the middle of the sukka

three tefachim,

it is

invalid,

because airspace invalidates the sukka at three tefachim.

The Mishna continues and explains three cases in which the halakha of “dofen akuma” validates the walls, so that they are considered walls adjacent to the schach.

a.

A house whose roof was breached

in its middle, distant from the walls on every side,

and one placed schach over it

over that place of the breach, and the part of the house’s ceiling that was not breached separates between the schach in the middle of the roof and the walls, then

if there is

a distance

from the wall

of the house, which is the wall of the sukka, to

the schach

in the middle of the house,

four cubits,

it is

invalid.

But if the distance between the schach and the walls of the house was less than four cubits, the sukka is valid.

And concerning the reason for this matter, the amoraim in the Gemara disagreed: there is one who holds that the measure of invalid schach that invalidates the sukka everywhere is four cubits, whether the invalid schach was placed in the middle of the sukka or whether it was placed at the side.

And there is one who holds that the measure of invalid schach that invalidates the sukka is four tefachim, except that if the invalid schach was placed at the side, adjacent to the wall, it does not invalidate the sukka until it is four cubits wide. Since there is a halakha given to Moses at Sinai to consider invalid schach placed at the side, adjacent to the walls, as though it were part of the wall that bent and folded upward, and consequently the walls are found to be adjacent to the schach [this halakha is called “dofen akuma”], and one who sits beneath the invalid schach is like one who sits beneath the wall.

b.

Likewise

the measure of the distance applies in

a courtyard surrounded by a portico

on three of its sides.

That is, there was a house built in the shape of the letter het, and in its center there was a courtyard.

Around the house, between the house and the courtyard, there was something like a balcony, with a roof over it, and this balcony—which is called an akhsadra—was open to the courtyard and surrounded it on three sides.

And if one placed schach over the airspace of the courtyard within the perimeter of the akhsadra, and the walls of the house served as the walls of the sukka in the courtyard, while the roof of the akhsadra, which is invalid schach, separated between the valid schach and the walls of the house, which now served [on their outer side] as the walls of the sukka, on their outer side—

then, if the width of the roof of the akhsadra was four cubits, the sukka in the courtyard is invalid, because the walls of the house, which are the walls of the sukka, are distant four cubits from the schach. But if the distance between the schach and the walls was less than four cubits, the sukka is valid, because we see the roof of the akhsadra as part of the wall that bent and reached the schach.

c. And likewise

a large sukka that was surrounded

on its roof, around it, adjacent to the walls,

with something with which one does not make schach, if beneath it there is

beneath that invalid schach a width of

four cubits,

the sukka is

invalid.

Gemara:

The Gemara asks:

All these

three cases in which our Mishna taught the law of “dofen akuma,”

why do I need them?

Is there a novelty in each one that is not present in the other?!

And the Gemara explains:

It is necessary!

For if it had taught us

the law of

a house whose roof was breached

alone, we would say that specifically in this case the halakha of “dofen akuma” was stated, to associate the partitions of the house with the sukka in the middle of the house,

because these partitions

are

for the house

in which the sukka was made that they were

made.

These partitions were made for the needs of the house, and it is this house that was made into a sukka; therefore, the halakha was stated to consider these walls as the partitions of the sukka through “dofen akuma.”

But in

a

courtyard surrounded by an akhsadra,

where one placed schach over the airspace of the courtyard surrounded by the akhsadra,

for the partitions

of the house that you seek to associate with the sukka in the courtyard through “dofen akuma,”

were not made for the akhsadra [

they were not made for the outer akhsadra], but rather for the house,

say no

the halakha of “dofen akuma” was stated to consider the walls of the house as part of the sukka. For this reason,

it is necessary;

our Mishna had to teach us that the halakha of “dofen akuma” was stated also in a courtyard surrounded by an akhsadra.

And if it had taught us

only

these two,

these two laws, of a house whose roof was breached and of a courtyard surrounded by an akhsadra, in which we say “dofen akuma,” we would say that specifically in them the halakha of “dofen akuma” was stated,

because their roofing

that separates between the valid schach and the wall is a “kind of

valid schach,

for even the ceiling of the house and the akhsadra is made of boards that do not contract ritual impurity and do not grow from the ground, and its only deficiency is that it was not made for the sake of a sukka but for the sake of dwelling, and it is invalid because of “you shall make it, and not [use something] already made.”

But a large sukka that they surrounded

above, between the walls and the valid schach,

with something with which one does not make schach,

such as types of metal, which contract ritual impurity and do not grow from the ground,

for its roofing

that separates between the valid schach and the wall is a “kind of

invalid schach, say no

shall we validate it through “dofen akuma.” Therefore

it is necessary

for our Mishna to teach us this law even in a sukka that they surrounded with invalid schach.

Rabba said: I found

them

the scholars of Rav’s academy [

the members of Rav’s academy],

sitting and saying

in Rav’s name: a.

Airspace invalidates

even a large sukka

at three

tefachim.

b.

Invalid schach invalidates

even a large sukka

at four

tefachim.

That is, a sukka that has only three walls, where airspace or invalid schach traversed it along its entire length: if that airspace was three tefachim wide, or that invalid schach was four tefachim wide, they invalidate the sukka. For through this separation the sukka is divided into two, and each of the parts of the sukka is found to have only two walls.

And I said to them [

I said to them in order to challenge their words]:

Airspace that invalidates at three

tefachim,

from where do you have this [

where do you derive it]? It is because

we learned

in our Mishna:

If one distanced the schach from the walls three tefachim,

the sukka

is invalid.

And from here you learned that airspace invalidates in a sukka at three tefachim.

If so, the same law applies to

invalid schach as well: should it not invalidate

in a sukka

except at four cubits,

and not as you said, at four tefachim?

For we learned

in our Mishna:

A house whose roof was breached

in its middle,

and one placed schach over it

over that breach, and the ceiling of the house separated between the valid schach placed in the middle of the roof and the walls of the house serving as the walls of the sukka

; if there is between the schach

the valid schach

and the wall

of the house

four cubits,

it is

invalid.

And it apparently emerges that invalid schach does not invalidate the sukka until four cubits?!

And they said to me,

the members of the academy:

That matter is excluded [

except for this clause]. That is, there is no proof from our Mishna that invalid schach does not invalidate a sukka until four cubits,

for Rav and Shmuel both say

to explain the reason for the Mishna:

they addressed the matter of dofen akuma

to validate it. That is, the reason for the validation is not that invalid schach does not invalidate until four cubits; rather, by the law of dofen akuma, we see the invalid schach placed at the side as part of the wall that bent and folded upward, and consequently the walls of the sukka are actually found to be adjacent to the schach.

And I said to them

to challenge their words further:

What if there is invalid schach less than four

tefachim in the middle of the sukka,

and

beside it there was

airspace less than three

tefachim, so that the invalid schach by itself does not have the measure that invalidates the sukka, and the airspace by itself likewise does not have the measure to invalidate the sukka,

what

do you say concerning this sukka? That it is

valid!

But if one

filled it

that airspace of less than three

with spits,

which are invalid for making schach, thereby completing the measure of four tefachim of invalid schach,

what?

For you say concerning the status of this sukka that it is

invalid.

And how is this possible?!

And

because

there will not be air,

the more stringent,

which invalidates with three

handbreadths,

like invalid schach,

the more lenient,

which invalidates with four?!

How is it possible that initially, when that place was not covered at all, but was mere air, which is more stringent and invalidates with three handbreadths, the sukka was valid, whereas now, when invalid schach, which is more lenient, has been made there, the sukka should be invalid?!

And they said to me

the Rabbis of Rav’s house:

If so,

if this matter is impossible, then

according to you, who say that invalid schach invalidates

everywhere

with four cubits, also

the same question will be difficult:

And

what if there is invalid schach less than four cubits

which does not invalidate the sukka,

and

beside it

air less than three

handbreadths,

what

do you say about it, that it is

valid!

Whereas if

you fill

that air

with spits,

and complete the measure of four cubits,

what

do you say about it? That it is

invalid!

It should be difficult for you:

there will not be air

the more stringent,

which invalidates with three

handbreadths,

like invalid schach

the more lenient,

which invalidates

with four cubits?!

And I said to them

to answer their objection to my words:

What is this,

for what comparison is this?!