- ומטבילין מגב לגב ומחבורה לחבורה
The Mishnah on Daf 17b concluded: ומטבילין מגב לגב ומחבורה לחבורה – We may immerse keilim from one purpose to another, or from one group to another. The Gemara here brings a Baraisa that taught: כיצד מגב לגב – What is an immersion from one purpose to another? הרוצה לעשות גתו על גב כדו וכדו על גב גתו עושה – If someone wishes to work his wine press by means of keilim that had been immersed for the purpose of his pitcher of oil, or vice versa, he may do so without immersing the keilim a second time. However, the Baraisa adds that if someone wants to be machmir and immerse his keilim a second time for their new function, he may perform this immersion on Yom Tov. Rashi explains that this is not considered tikkun kli, since the tevillah was not required for any purpose. The Baraisa continues that if someone was planning on shechting and eating the pesach with one chaburah and then changes his mind and intends to eat with another chaburah, הרשות בידו – he may do so without immersing. However, the Baraisa adds that if someone wants to be machmir and toveil to join another chaburah, he may do so on Yom Tov.
- Machlokes about bringing olos and shelamim on Yom Tov
The next Mishnah states: Beis Shammai say: מביאין שלמים ואין סומכין עליהן אבל לא עולות – We may bring shelamim on Yom Tov, however, we may not do semichah on them, but we may not bring olos. But Beis Hillel say: מביאין שלמים ועולות וסומכין עליהן – We may bring both shelamim and olos on Yom Tov, and we may do semichah on them. Ulla said: מחלוקת בשלמי חגיגה לסמוך ועולת ראייה ליקרב – The machlokes is with the shalmei chagigah regarding the requirement of semichah, and the olas re’iyah regarding its offering. For Beis Shammai hold that since the passuk states: "וחגתם אתו חג לה'" – You shall celebrate it as a holiday unto Hashem, חגיגה אין עולת ראיה לא – the chagigah may be offered but the olas re’iyah may not. But Beis Hillel hold that the passuk can be interpreted to include olos, as the passuk states: "לה' " – unto Hashem, which implies כל דלה' – anything that is offered to Hashem in connection to the chag may be brought on Yom Tov. אבל נדרים נדבות דברי הכל אין קריבין ביום – However, everyone agrees that vowed or donated offerings – whether olah or shelamim – may not be offered on Yom Tov. The Gemara attempts to challenge Ulla’s interpretation.
- Machlokes Tannaim regarding when a Todah may be offered
The Gemara bring another machlokes Tannaim in regard to offering nedarim and nedavos on Yom Tov. It was taught in a Baraisa: אין מביאין תודה בחג המצות מפני חמץ שבה – We may not bring a Torah on the Pesach because of the chametz that is in it. ולא בעצרת מפני שהוא יום טוב – nor may we bring it on Shavuos because it is Yom Tov. The Gemara will explain that this Tanna holds that nedarim and nedavos cannot be brought on Yom Tov. אבל מביא אדם תודתו בחג הסוכות – but a person may bring his Todah on Succos, which Rashi explains refers to Chol HaMoed. Rebbe Shimon disagrees and says that since all three chagim are juxtaposed in the same passuk of בחג המצות ובחג השבעות ובחג הסכות, it indicates that whatever which may be brough on Pesach, may be brought on Shavuos and Succos, but any offering that may not be brought on Pesach, may not be brought on Shavuos and Succos. Rebbe Elazar b’Rebbe Shimon says, מביא אדם תודתו בחג הסוכות – a person may bring his Todah on Succos, ויוצא בה ידי חובתו משום שמחה ואין יוצא בה משום חגיגה – and fulfill his chiyuv of simchah, but not his chiyuv of chagigah. Rashi explains that a chagigah is mandated by the principle of כל דבר שבחובה אינו בא אלא מן החולין – any mandatory offering may only be brought from chullin. Since the person has already become obligated to bring his todah, it may not be used for another obligation.