Menachos Daf 103 מנחוס דַף 103

The next Mishnah states that one who says: הרי עלי מנחה מן השעורים – “It is hereby upon me to bring a minchah from barley” (which is impossible for a voluntary minchah), יביא מן החטים – he must bring [a minchah] from wheat. Similarly, if he vowed to bring a minchah of קמח – ordinary flour (instead of סולת – fine flour), or without oil and לבונה, or only half an עשרון, he must bring a proper minchah. 

The Gemara asks that he should be exempt, because this impossible stipulation should be considered an immediate retraction!? Chizkiyah says this Mishnah follows Beis Shammai, who holds תפוס לשון ראשון – grasp (i.e., give primacy to) the first phrase. Therefore, his pledge to bring a minchah requires bringing one properly, and his second expression is ignored. Rebbe Yochanan says Beis Hillel can agree with the Mishnah, and the case is where he said אילו הייתי יודע שאין נודרין כך – “Had I known that one cannot vow this [improper way], לא הייתי נודר כך אלא כך – I would not have vowed this way, but that way (i.e., a proper minchah).” Chizkiyah later agrees with Rebbe Yochanan’s interpretation, noting that the Mishnah specifically discussed a נדר to bring a minchah of barley (a reasonable error), but not one who vowed a minchah of lentils.

The next Mishnah teaches that one may donate a minchah of up to sixty עשרונות and bring it in a single כלי, but if he donates a minchah of sixty-one עשרונות, it must be divided into two כלים. The Mishnah first explains that since the ציבור brings a total of sixty-one עשרונות on Succos which falls out on Shabbos, an individual should bring one עשרון fewer. However, Rebbe Shimon objects to this reason (since the ציבור’s menachos cannot be mixed together), and explains instead: עד ששים יכולין ליבלל – until sixty עשרון [the flour and oil] are able to be mixed, but not with more than sixty עשרון. They asked him, is it possible that sixty עשרון can be mixed, but sixty-one cannot? He replied: כל מדות חכמים כן – all the Sages’ measurements are so, i.e., precise. For example, a person can immerse himself in forty סאה, but not in forty סאה minus a קורטוב (1/64 of a לוג). In a Baraisa, Rebbe Shimon provides more examples: a כביצה of food can transmit tumah, but the volume of a sesame seed less cannot. Cloth which is three by three tefachim can contract טומאת מדרס, but a single thread less cannot.

Rebbe Shimon explained that a נדר of sixty-one עשרונות must be divided into two כלים, because this amount of flour cannot be properly mixed with the oil. The Gemara asks why this is a problem, since a Mishnah states: אם לא בלל כשר – if he did not mix the flour and oil, [the minchah] is still valid!? Rebbe Zeira answers: כל הראוי לבילה – any [minchah] fit for mixing the flour and oil, אין בילה מעכבת בו – the mixing is not critical and the minchah is valid without it, וכל שאינו ראוי לבילה – but any [minchah] which is unfit for mixing (because of the incorrect proportion of flour to oil), בילה מעכבת בו – the mixing is critical to it, and the minchah is invalid.