Makkot 17A

קורא את השם, ואינו צריך להפריש.

He designates a portion of the produce by means of calling the name upon poor man’s tithe, but he is not required to physically separate that portion and give it to the poor.

מאי לאו בהא קא מיפלגי, דמר סבר: ודאי ⁠– טובלו. ומר סבר: ודאי ⁠– אינו טובלו? אמר ליה אביי: אי הכי, אדמיפלגי בספיקו, ליפלגו בודאי!

Rav Yosef suggests: What, is it not that they disagree with regard to this: That one Sage, the Rabbis, holds that produce from which poor man’s tithe was certainly not separated is rendered untithed produce, and therefore, in a case where there is uncertainty whether poor man’s tithe was separated, one is required to separate it; and one Sage, R' Eliezer, holds that produce from which poor man’s tithe was certainly not separated is not rendered untithed produce, and therefore, one need not even designate poor man’s tithe by calling its name upon a portion of the produce? Abaye said to Rav Yosef: If it is so, that this is the point in dispute, rather than disagreeing with regard to a case of uncertainty whether poor man’s tithe was separated, let them disagree with regard to a case of certainty that poor man’s tithe was not separated.

אלא, דכולי עלמא ודאי ⁠– טובלו. והכא בהא קא מיפלגי, מר סבר: לא נחשדו עמי הארץ על מעשר עני של דמאי. כיון דממונא הוא ⁠– אפרושי מפריש. ורבנן סברי: כיון דטריחא ליה מילתא ⁠– לא מפריש.

Rather, contrary to the previous suggestion, say that everyone agrees that produce from which poor man’s tithe was certainly not separated is rendered untithed produce. And here, it is with regard to this that they disagree: One Sage, R' Eliezer, holds: Amei ha’aretz are not suspected of refraining from separating poor man’s tithe of demai. Since it is merely a matter of money, and no sanctity is involved, he separates poor man’s tithe, although he does not actually give it to the poor. And the Rabbis hold: Since the matter involves exertion for him, he does not even separate poor man’s tithe.