Beitzah 34B

ערב שבת בשביעית, ואומר: מכאן אני אוכל למחר. וחכמים אומרים: עד שירשום ויאמר מכאן ועד כאן.

on Friday during the Sabbatical Year, during which no tithes are separated, which means one may take fruit on the following day without the need for any corrective measure, and say: From here, from these fruits, I will eat tomorrow. And the Rabbis say: He may not eat unless he marks the pile of fruit the day before and explicitly says: From here to there I will take.

גמ׳ תנן התם: תינוקות שטמנו תאנים מערב שבת ושכחו ולא עשרו ⁠— למוצאי שבת לא יאכלו אלא אם כן עשרו. ותנן נמי: המעביר תאנים בחצרו לקצות ⁠— בניו ובני ביתו אוכלין מהן עראי ופטורים.

Talmud: We learned in a Mishnah there: (Ma'asrot 4:2) Children who hid figs for themselves in a field on Friday in order to eat them on Shabbat, and they forgot and did not separate tithes, not only are they prohibited from eating them on Shabbat, for eating on Shabbat is always considered a fixed meal that obligates the produce in tithes, but even after the conclusion of Shabbat, they may not eat until they have separated tithes. And we also learned in a Mishnah: One who transfers figs in his courtyard in order to make them into dry figs, his children and the members of his household may in the meantime partake of them in a casual manner, and they are exempt from tithes. The fact that the fruit has reached his courtyard, as opposed to his house, is not enough to cause it to be liable for tithing.

בעא מניה רבא מרב נחמן: שבת, מהו שתקבע מוקצה למעשר בדבר שלא נגמרה מלאכתו? מי אמרינן, כיון דכתיב: ״וקראת לשבת עונג״, קבעה ואפילו בדבר שלא נגמרה מלאכתו, או דלמא: בדבר שנגמרה מלאכתו ⁠— קבעה, בדבר שלא נגמרה מלאכתו ⁠— לא קבעה?

Based on these two sources, Rava inquired of Rav Naḥman: With regard to Shabbat, what is the halakha in terms of whether it establishes an obligation to tithe food that has been muktze on Shabbat? Specifically, in the case of an item whose labor has not been completed, does the fact that the food is muktze on Shabbat give it the status of completely prepared food, or not? Do we say that since it is written: “And call Shabbat a delight” (Isaiah 58:13), this implies that any food one eats on Shabbat is considered a delight and not a casual meal, and therefore Shabbat establishes an obligation to tithe, as if the food were fully completed and fit to be eaten as a fixed meal, even for an item that has not had its labor completed? Or perhaps Shabbat establishes an obligation to tithe an item whose labor is completed, but regarding an item whose labor is not completed it does not establish an obligation to tithe?