• Four times a year, a seller must disclose a prior sale of the animal’s parent or offspring

The next Mishnah teaches that on four days a year – the days before שמיני עצרת, Pesach, Shavuos, and Rosh Hashanah – a seller who already sold an animal’s mother or daughter for shechitah that day must inform the next buyer. Since these are major Yom Tov preparations, the first animal will likely be shechted that day, raising the prohibition of אותו ואת בנו. Rebbe Yehudah  limits this requirement to sales made on the same day, but if the first sale occurred on a previous day, he need not inform the buyer. Still, if he sold the mother to a groom and the daughter to his bride, he must notify the second buyer, since both are likely to be shechted the same day. On these four days, משחיטין את הטבח בעל כרחו – we force a butcher to shecht against his will, even if only a small portion of an expensive animal was sold. Therefore, if it dies, the buyer loses his portion. The Gemara proceeds to explain how the buyer acquired his portion without משיכה – pulling near.

• The day follows the night regarding אותו ואת בנו

The next Mishnah states: regarding the “one day” written about the prohibition of אותו ואת בנו,היום הולך אחר הלילה – the day follows the night (i.e., each “day” begins and ends at nightfall). Rebbe Shimon ben Zoma darshened that the term "יום אחד" – one day is mentioned both in מעשה בראשית and regarding אותו ואת בנו. Just as in בראשית, where ויהי ערב – there was evening and then ויהי בוקר – there was morning establishes that the morning follows the night, the same applies to אותו ואת בנו. A Baraisa explains why this derashah was necessary. Since אותו ואת בנו appears in a section discussing korbanos, one might have thought that אותו ואת בנו follows the law of korbanos, where the night follows the day (because the Torah requires eating a קרבן תודה “that day,” and says not to leave over any of it “until morning,” indicating that the night is part of “that day”). The gezeirah shavah from מעשה בראשית teaches to follow the בראשית model.

• כסוי הדם applies only to chullin and not kodashim

The sixth Perek discusses the mitzvah of כסוי הדם – covering the blood of a shechted חיה or bird. It states: כסוי הדם נוהג בארץ ובחוצה לארץ – the mitzvah of covering the blood applies both in Eretz Yisroel and outside Eretz Yisroel, whether or not the Mikdash stands, but only to חולין animals, and not kodashim. It applies to חיות and birds (but not בהמות). The Gemara suggests that kodashim is excluded because Rebbe Zeira ruled: השוחט צריך שיתן עפר למטה ועפר למעלה – one who shechts must place earth under the blood and earth above it. Earth cannot be placed under the blood of a korban bird on the מזבח: permanently placed earth would improperly alter the מזבח’s structure, and temporary earth would constitute a problematic חציצה. Although placing earth beneath the blood is ordinarily not מעכב, it is מעכב here, since it is impossible to fulfill properly (because it is "אין ראוי לבילה"). However, the Gemara challenges this explanation, because one could scrape the blood off the מזבח and perform כסוי properly!? Therefore, the exclusion of kodashim is explained differently on the next Daf.

Siman – Pogo Stick. The Chol Hamoed pogo stick performer, who went to purchase a cow erev Yom Tov and was told that the mother was sold earlier that day, asked if it was sold before or after nightfall because, for אותו ואת בנו, the new day starts at night, and needed the meat to have the strength to do his double-flip כיסוי הדם trick on חיות and birds that are חולין, skipping the ones that are קדשים.