Sukkah 17b (יז:) — the Talmud in English

Granted, according to my view, that I say

that invalid roofing does not invalidate the sukka until

four cubits,

as we likewise learned in the Mishna regarding a house whose roof was breached ,

because it is a measure, whereas this is not a measure.

That is, the reason that invalid roofing four cubits wide invalidates the sukka is that it contains the requisite “measure” for invalidating it. By contrast, invalid roofing less than four cubits wide does not invalidate the sukka, because it lacks the “measure” required to invalidate it. This measure is a halakha given to Moses at Sinai, like the other measures of the Torah.

Therefore, one cannot object that the air beside it should combine with it to reach a measure of four cubits, since

this—

the combination of the invalid roofing and the air—

is not a measure;

it is not considered invalid roofing four cubits wide,

since their measures are not equal

[the measures of invalid roofing and air]

to one another,

for air invalidates with three handbreadths, whereas roofing invalidates with four cubits; therefore,

they do not combine

to complete one measure.

But according to you, who say that the measure

of invalid roofing required to invalidate the sukka is four handbreadths

because of separation,

the basis of this measure is that four handbreadths are considered throughout the Torah to be an independently significant “place.” Accordingly, here too, when the invalid roofing was four handbreadths wide, it is considered an independent place and divides the sukka, making it like two sukkot, neither of which has three walls.

If so,

what difference is it to me

whether

the sukka is divided

by invalid roofing,

or what difference is it if it is divided by invalid roofing and air?

Ultimately, there are four handbreadths in the middle of the sukka, which is the measure of an independently significant “place” that is unfit for sitting, and it should divide the sukka?!

Abaye said

to Rabba:

And according to the Master as well,

who holds that invalid roofing does not take effect until it reaches the requisite measure, why should the air not combine with it to complete the deficient measure of the invalid roofing?

Indeed,

although

[even]

their measures are not equal

[the measures of invalid roofing and air are not equal] to invalidate it

in a large sukka

larger than the measure of seven handbreadths: the measure of invalid roofing is four cubits, whereas the measure of air is three handbreadths, and they do not combine to complete one measure,

nevertheless,

in a small sukka,

which is only seven handbreadths wide,

are their measures not equal?!

Certainly, in this sukka, if three handbreadths are missing from its measure and it thereby leaves the category of “lavud,” whether this resulted from air or from invalid roofing, it is invalid, since it does not contain the measure of a valid sukka covered with valid roofing. And since, with regard to a small sukka, their measures are equal, perhaps even in a large sukka the air should combine with the invalid roofing to complete the deficient measure and invalidate it?!

Rabba said

to Abaye:

There,

in a small sukka, where even invalid roofing invalidates with three handbreadths,

it is not because their measures are equal to one another.

It is not because their measures are equal, such that you would say that in a small sukka the measure of invalid roofing and that of air are one and the same.

Rather,

the reason that even invalid roofing invalidates a small sukka with three handbreadths

is because the measure of

a valid

sukka

covered with valid roofing is absent

from it.

The Gemara raises an objection:

And

is it the case that

whenever the measures are not equal

of two things

to one another,

they

do not combine?

A. The “bed of a zav” is impure and becomes a primary source of ritual impurity, as it is stated [Leviticus 15:4]: “Every bed upon which the zav lies shall be impure.”

B. A zav renders his bed or seat impure only if they were designated for that purpose and were fit to serve as a bed or seat. The measure required for them to be fit for this purpose will be explained in the Mishna below.

But didn’t we learn

[Kelim 27b]:

A garment

designated as the bed of a zav has, with regard to contracting impurity as the bed of a zav, a minimum measure of

three

handbreadths

by three

handbreadths.

The measure of

a sack

[made of goat hair and thicker than a garment] is at least

four

handbreadths

by four

handbreadths.

The measure of

leather is five

handbreadths

by five

handbreadths.

The measure of

a mat

[a mat made of ropes ] is

six

handbreadths

by six

handbreadths.

And it was taught concerning it,

a beraita was taught concerning this Mishna:

A garment,

the more susceptible, which contracts impurity with three handbreadths,

and a sack,

the less susceptible than it, which contracts impurity only with four handbreadths, if they were joined together to make a single sheet four handbreadths by four handbreadths, and likewise

a sack,

the more susceptible, which contracts impurity with four handbreadths,

and leather,

the less susceptible than it, which contracts impurity only with five handbreadths, if they were joined together and together completed a measure of five by five handbreadths, the measure for leather to contract impurity, which is the least susceptible of them,

And likewise,

leather and a mat,

if they were joined together to make a single sheet six handbreadths by six handbreadths, the measure of the mat, which is the less susceptible of them,

these

combine with one another.

This proves that even two things whose measures are not equal combine with one another, and the material whose measure is smaller completes the material whose measure is larger than it. If so, likewise with regard to a sukka, the air, whose measure for invalidating the sukka is smaller than the measure of invalid roofing, should combine with it to complete the measure of invalid roofing, four handbreadths. The Gemara answers: In general, two types whose measures are not equal do not combine.

There,

where we find different types combining with regard to impurity of a zav’s bed, it is

as the reason is taught

in that same beraita:

Rabbi Shimon said: What is the reason

that two types combine to complete the measure for contracting impurity even though their measures are not equal?

Since each is fit

by itself

to render a seat impure.

That is, with regard to impurity of a seat, their measures are equal, as will be explained below. Since their measures are equal with regard to one of the types of impurity caused by a zav—the impurity of a zav’s seat—they combine even with regard to another type of impurity caused by a zav, the impurity of a zav’s bed.

As we learned

[Kelim 27:4]:

One who trims,

cutting with a knife all around into a pleasing shape,

from all of them,

from any one of the types mentioned above, even if that piece was only

one handbreadth by one handbreadth,

it is

impure

with the impurity of a zav’s bed.

The Gemara explains:

What is one handbreadth by one handbreadth fit for?

[And why is that handbreadth fit] such that it should thereby be fit to contract impurity as a zav’s bed?

And Rabbi Shimon ben Lakish said in the name of Rabbi Yannai: Since it is fit to be taken

and made into a patch

on

the saddlecloth of

a donkey,

in the place where a person sits upon the saddlecloth. Therefore, if one made a patch from them for a saddlecloth and designated them for that purpose, they contract the impurity of a zav’s seat. All these types have equal measures for this purpose. Since they are equal with regard to this, they also combine to complete the measure for the impurity of a zav’s bed.

In Sura they stated this tradition

above, concerning the measure of invalidation of invalid roofing placed in the middle of the sukka,

with this wording

[in this formulation], as it was cited above. According to this formulation, Rav holds that invalid roofing invalidates in the middle of the sukka with four handbreadths, whereas Rabba holds that even when the invalid roofing is placed in the middle of the sukka, it does not invalidate it until four cubits.

But

in Nehardea they taught

this dispute differently. According to the formulation of Nehardea, it is Shmuel who holds that invalid roofing invalidates in the middle of the sukka with four handbreadths, while Rav disputes him and maintains that invalid roofing does not invalidate even in the middle of the sukka until four cubits.

And this is how they taught in Nehardea:

Rav Yehuda said in the name of Shmuel: Invalid roofing in the middle

of the sukka

invalidates with four

handbreadths. But if the invalid roofing was placed

at the side,

immediately adjacent to the walls, it

invalidates

only

with four cubits,

at which point it leaves the category of “a crooked wall.”

And Rav said: Whether at the side

or

whether in the middle, with four cubits.

We learned above, on 14a: One may roof with boards, according to Rabbi Yehuda; Rabbi Meir prohibits it, and his reason is the “decree due to a ceiling.”

The Gemara debated which boards were the subject of the dispute between Rabbi Meir and Rabbi Yehuda.

According to Rav, even Rabbi Meir invalidated only boards four handbreadths wide; but boards less than four handbreadths wide are valid for roofing according to everyone.

According to Shmuel, boards four handbreadths wide are unfit for roofing even according to Rabbi Yehuda, and they disagree with regard to boards more than three and up to four handbreadths wide: Rabbi Meir prohibits roofing with them because of the decree due to a ceiling, while Rabbi Yehuda permits it.

We learned: If one placed upon it a board four handbreadths wide,

which is unfit for roofing because of the “decree due to a ceiling,” the sukka is

valid.

The Gemara assumed that the board was placed in the middle of the sukka, and therefore it asks:

Granted, according to Rav

[according to the version of the people of Nehardea],

who says that whether in the middle or at the side, it is four cubits, for this reason,

if one placed upon it a board only four handbreadths wide, even if it was in the middle, it is

valid,

since invalid roofing does not invalidate the sukka until four cubits.

But according to Shmuel, who says

that invalid roofing placed

in the middle

of the sukka invalidates

with four

handbreadths,

why is it valid

when one placed in its middle a board four handbreadths wide?!

The Gemara answers:

With what are we dealing here?

For example, it was placed

at the side.

With regard to the side, everyone agrees that the sukka is not invalidated until four cubits, since this invalid roofing is considered part of the wall by virtue of the halakha of “a crooked wall.”

Come and hear

from that which we learned there: If one placed upon his sukka

two sheets

that contract the impurity of garments and are unfit for roofing because they are susceptible to ritual impurity, and neither one individually contained the measure required to invalidate the entire sukka, nevertheless, since they were placed side by side, they

combine

to invalidate it.

But

two boards

that are wide but neither one contains the measure required to invalidate the sukka

do not combine

to invalidate it, since according to the first tanna the Sages did not decree that wide boards are unfit for roofing because of the “decree due to a ceiling.”

Rabbi Meir says:

Even

boards

combine with one another

like sheets.

Rabbi Meir holds that one may not roof with wide boards because of the “decree due to a ceiling,” as explained above, on 14a. The amoraim there disputed his view: whether a board three handbreadths wide is unfit for roofing, or only one four handbreadths wide; according to Rav, only boards four handbreadths wide were prohibited.

And this is difficult:

Granted, according to that formulation

that they taught in Nehardea,

where Rav says

that invalid roofing

whether in the middle or at the side is four cubits, what does “they combine” mean

as taught in the beraita,

they combine to reach four cubits?

This is referring to a case where the sukka was roofed with boards four handbreadths wide, which are unfit for roofing, placed side by side until together they reached a width of four cubits, thereby invalidating the entire sukka.

The explanation of the dispute between the tannaim in the beraita is as follows: Rabbi Meir prohibits it, since according to his view boards four handbreadths wide are invalid because of the decree concerning a roof; and since they were placed adjacent to one another, they combine to invalidate the entire roofing when they occupy four cubits. Whereas the first tanna holds in accordance with Rabbi Judah, that the Sages did not decree at all that boards are invalid, even when they are four handbreadths wide. Therefore, they certainly do not combine to occupy four cubits and invalidate it, since they are valid roofing.

But according to this formulation

(the first formulation, which holds)

that Rav said that

invalid roofing placed

in the middle

of the sukka invalidates it

with four

handbreadths,

what are the circumstances?

What kind of boards is the beraita discussing?

If they have

a width in each of the boards of

four

handbreadths and are invalid for roofing, then

why do they need to combine?

For even if they do not combine, each one individually has the measure necessary to invalidate the entire sukka.

And

if they do not have

a width in each of the boards of

four

handbreadths, sufficient for a single board to invalidate it by itself, then why should they combine? After all,

they are merely reeds,

like other reeds,

are they,

and they are valid roofing. For according to Rav, even Rabbi Meir did not prohibit roofing with boards that are not four handbreadths wide; so how could they combine to invalidate it?!

The Gemara answers:

In fact,

the case is

that they have

a width in each of the boards of

four

handbreadths, and they are invalid for roofing.

And what does “they combine” mean,

that is, in what manner must they combine in order to invalidate the sukka? —

They combine to occupy four cubits along the side.

For example, they were placed along the side, adjacent to the wall. Therefore, although they are invalid for roofing, the sukka is not invalidated by one of them alone without their combining, since invalid roofing placed along the side does not invalidate the sukka until it occupies four cubits, because of the principle of a crooked wall.

Come and hear

from that which we learned there:

If one roofed

his sukka

with cedar boards that have

a width, in each and every one of them, of

four

handbreadths,

everyone agrees that it is invalid.

But if

they do not have,

in each and every one of them

, four

handbreadths,

Rabbi Meir deems it invalid, and Rabbi Judah deems it valid.