Nedarim 88

ודלמא אתי לעשורי מן החיוב על הפטור ומן הפטור על החיוב

but perhaps he will come to tithe from [produce] that is liable for [produce] that is exempt, or vice versa?<span class="x" onmousemove="('comment',' The tithe could be separated from one lot of produce upon another (of the same species), providing that both bore the same liability. E.g if one harvests his two fields, he can take From one the tenth of the combined produce. If, however, he separates a tithe of one field, thus freeing the rest, he cannot take another tithe from the same for the second field. Similarly, if he has two lots of corn, one liable to tithe by Biblical law, and the other only by Rabbinical law, so that by Biblical law it is really exempt, he may not separate from the one for the other. Now it has been explained here that according to R. Jose, so long as no stranger has taken possession, it is not hefker by Biblical law even after three days. and consequently Biblically liable. But by Rabbinical law it is hefker, even if the original owner re-acquires it. Nevertheless, as explained on p. 139, n. 5, the Rabbis ordered that he shall tithe it. Thus, in this respect, the Rabbis restored it to Biblical law. But the owner, being told that it is hefker, may regard the liability to tithe as merely a Rabbinical measure, and therefore, if he has any other corn which is only Rabbinically liable, separate from the one, which is really Biblically exempt, For the Biblically liable, or vice versa. ');">¹</span> — He is told, 'When you tithe, tithe for it out of itself.'<span class="x" onmousemove="('comment',' Only in this respect is it regarded as hefker even if the first owner resumes possession. ');">²</span>

דאמרי' ליה כי מעשרת עשר מיניה וביה

An objection is raised: If a man declares his vineyard hefker and rises early on the following morning and vintages it,<span class="x" onmousemove="('comment',' Thus he resumed possession thereof. ');">³</span> he is liable to peret,<span class="x" onmousemove="('comment',' Single grapes fallen off during the cutting, which must be left for the poor. — Lev. XIX, 10. ');">⁴</span>

מיתיבי המפקיר את כרמו ולשחר עמד ובצרו חייב בפרט ובעוללות ובשכחה ובפיאה ופטור מן המעשר

'oleloth,<span class="x" onmousemove="('comment',' 'Olelah, 'oleleth, pl. 'oleloth, gleanings reserved for the poor; in general, a small single bunch on a single branch. Ibid. and Deut. XXIV, 21. ');">⁵</span> the forgotten sheaves,<span class="x" onmousemove="('comment',' Sheaves (here grapes) forgotten in the course of ingathering, which had to be left for the poor. — Deut. XXIV, 19. ');">⁶</span>

בשלמא לעולא דרבנן קתני לה ודאורייתא קתני לה אלא לריש לקיש אמאי פטור מן המעשר

and <i>pe'ah</i>,<span class="x" onmousemove="('comment',' Pe'ah — corner; the corner of the field left for the poor. — Lev. XIX, 9. ');">⁷</span> but he is exempt from tithe. Now as for 'Ulla, it is well: it states the rabbinic law, and states the Biblical law.<span class="x" onmousemove="('comment',' 'Ulla maintains that the Baraitha in stating that he can retract within the first three days, teaches the Rabbinical law, whereas this Baraitha states the Biblical law according to which it is hefker immediately. ');">⁸</span>

אמר לך כי אמרי אנא לר' יוסי הא רבנן היא

But on the view of Resh Lakish, why is he free from tithe?<span class="x" onmousemove="('comment',' Since he maintains that within the first three days it is not hefker even by Biblical law, and hence subject to tithes, and even after that it is hefker only by Rabbinical law, why is it taught here that on the very next day it is free from tithe? ');">⁹</span> — He answers you thus: My statement is based on R. Jose; whilst this accords with the Rabbis.<span class="x" onmousemove="('comment',' Who maintain in the Mishnah that it is hefker immediately, hence free from tithe. ');">¹⁰</span>