Bava Batra 55b — the Talmud in English

And

a public thoroughfare

[a road sixteen cubits wide], and it is a place for the passage of horses and wagons belonging to the public -

And

a private road

[a road four cubits wide] -

And a public path

is a road for the public to travel on foot

and a private path -

that is fixed

ye

both during the summer days and during the rainy season,

because it is not a place of plowing and sowing, and therefore people travel on it even during the rainy season.

And concerning the obligation of peah for each field, Rabbi Yohanan said: even a boundary and a ḥatzav interrupt within a field, and one must leave peah from each one.

The Gemara further explains:

What is the matter of impurity

[with regard to which law concerning impurity does an interruption between two fields help]?

For we learned

in tractate Teharot:

One who enters a valley -

which has many fields -

during the rainy season

since people do not travel there [so that they should not damage the sowing], and it has the status of a private domain with regard to that which we hold: “uncertainty concerning impurity in a private domain—it is impure,”

and

there is

impurity in

within

a certain field

[and not throughout all of it],

and

the one who entered the valley said: “

I went to that place

[to the valley],

and I do not know whether I entered that place [the field in which there is impurity],

and even if I entered, I do not know whether I went as far as the grave and became impure through being under its tent,

or not”:

Rabbi Eliezer declares him pure

even though it is a private domain, where its uncertainty is impure, as he proceeds to explain the reason.

And the Sages declare him impure

in accordance with the law of a private domain, whose uncertainty is impure.

For Rabbi Eliezer would say:

If the uncertainty were

an uncertainty concerning entry,

that is, when the uncertainty is whether he entered at all into the field in which there is impurity, then he is

pure,

even though it is a private domain, and for this reason he declared one who entered a valley pure.

And only if the uncertainty were

an uncertainty concerning contact with impurity,

that is, he certainly entered the field, but he does not know whether he reached the place of the impurity, then he is

impure

in a private domain.

And concerning Rabbi Eliezer’s law, the boundary and the ḥatzav interrupt: if there was impurity somewhere in the field on one side of the boundary, and it is uncertain whether he entered on this side or not, he is not impure, for this is “an uncertainty concerning entry.” But if there was a large field in which no boundary interrupts in the middle, and he knows that he entered the large field but does not know whether he walked on the side where the impurity is, this is “an uncertainty concerning contact with impurity,” and he is impure, because everything is considered one field, and he has indeed come [to it].

And the Gemara infers: since Ravin, in the name of Rabbi Yohanan, disputed only concerning peah and impurity, that the boundary and the ḥatzav interrupt, and did not also dispute with regard to Shabbat, it follows:

but with regard to Shabbat, they do not

the boundary and the ḥatzav interrupt; and it proceeds to explain what interruption between two fields has to do with Shabbat.

Rava said: even with regard to Shabbat

they interrupt.

And the Gemara explains with regard to what the interruption is effective in the laws of Shabbat:

For it was taught:

If

he carried out

a person food on Shabbat measuring

half a dried fig

[which is half the measure of carrying out food, to make one liable for a sin-offering on Shabbat], from a private domain

to a public domain, and placed it

in the public domain

; and he again carried out

a measure of

another half dried fig

and placed it there:

If

in one lapse of awareness

he carried them out, without remembering in the interim that today was Shabbat—then he is

liable

for a sin-offering.

And if

in two lapses of awareness

he carried them out, having remembered between one carrying-out and the other that today was Shabbat, then he is

exempt,

because “knowledge divides [the] sin-offerings”; that is, knowledge that he acquired between the two carrying-outs divides the carrying-outs into two, so that neither one contains the measure, and he is exempt.

Rabbi Yose says:

Even

in one lapse of awareness

there is a division in the matter: