Nedarim 44b — the Talmud in English

And

since this is so, there is room for concern

lest he come to tithe from that which is subject to the tithe onto that which is exempt,

namely, that the one who acquired it will say: Since the Sages granted me what I acquired—certainly it is complete hefker, and what the one who declared it hefker retracted is legally nothing, and in truth I am exempt from the tithe. And this that they obligated me in the tithe is only by rabbinic enactment, because of the decree concerning those who see it, who will see that the one who declared it hefker retracted, and will think that his retraction is considered a retraction, and they too will come to declare [their property] hefker and retract afterward; therefore they enacted that the one who acquired it must tithe. But in truth the retraction of the one who declared it hefker is nothing, for if so, how did they grant me his hefker!? And the one who acquired it will come to tithe from this thing that he acquired, since he thinks that it is exempt from the tithe, onto another thing that is truly exempt by law from the tithe, such as wheat that grew in an unperforated flowerpot, and in truth this tithe does not take effect at all

! And

there is likewise concern lest he come to tithe

from that which is exempt onto that which is subject to the tithe,

namely, from the produce of an unperforated flowerpot onto what he acquired!

And we answer: There is no concern for this, because

we say to him

who acquired it:

When you tithe,

when you tithe what you acquired,

tithe

specifically

from it—

and upon it.

That is, tithe specifically from it—upon it, and not from it onto another thing, and not from another thing onto it.

We raise an objection: One who declares his vineyard hefker, and on the morrow

in the morning of the following day

—stood and harvested it

after acquiring it anew

is liable for peret, for olelot, for forgotten sheaves, and for the corner,

because an extra word “you shall leave” was written concerning them, to obligate the owner himself who declared them hefker, if he went back and acquired them [but if he did not go back and acquire them, in truth the vineyard is also exempt from these things, by the law of hefker].

And he is exempt from the tithe,

since an extra “you shall leave” was not stated concerning it.

And now,

granted according to

the method of

Ulla

who established the entire earlier beraita according to the method of the Rabbis, this beraita

teaches it according to the Rabbis,

that is, it is according to the method of the Rabbis, and in truth within three days he can retract, and consequently he will be liable for the tithe.

And

the beraita—the law

of the Torah it teaches it.

For by Torah law he cannot retract, and therefore he is exempt from the tithe.

But according to Reish Lakish,

who establishes the earlier beraita according to Rabbi Yosei,

why is he exempt from the tithe?

For since according to Rabbi Yosei’s method he can retract, then when he stood and harvested it, we have no proof that he intended to acquire it from the hefker, and it is possible that he now retracted from his hefker—and it was revealed that it had never been hefker at all, and he is liable for the tithe.

He can say to you

Reish Lakish:

When I say this according to Rabbi Yosei,

it is specifically concerning the earlier beraita. But

this,

this beraita, necessarily follows the method of

the Rabbis

and not the method of Rabbi Yosei.