Zevachim Daf 6 זבחים דַף 6

The Gemara asks: אעשה דלאחר הפרשה מכפרא – does [an עולה] atone for a positive commandment transgressed after [the korban’s] designation, או לא מכפרא – or does it not atone for it? Does an עולה operate in the way a חטאת does, so just as a חטאת cannot atone for a sin committed after its הפרשה, so too an עולה cannot atone for an עשה transgressed after the עולה’s הפרשה? Or is an עולה different from a חטאת, because whereas with a chatas, על כל חטא וחטא בעי לאיתויי חדא חטאת – for each and every sin he must bring a separate chatas, but regarding an olah, כיון ד[אי] איכא כמה עשה גביה מכפרא – since if there are several violations of positive commandments with him, it atones for all of them, so perhaps it can even atone for transgressions after the הפרשה.

The Gemara suggests a proof: The passuk uses the word "ונרצה" – and it shall be acceptable in reference to סמיכה – leaning on a korban before shechitah. Since כפרה is accomplished with the blood of a korban, a Baraisa explains that this passuk teaches שאם עשאה לסמיכה שירי מצוה – that if he treated semichah as “residue” of a mitzvah (i.e., unimportant) and did not do it, מעלה עליו הכתוב כאילו לא כיפר וכיפר – the passuk considers it for him as if it did not atone, but it actually did atone. This expression presumably means to say that although the korban atoned for any עשה transgressed before the korban’s designation, but it did not atone for his failure to perform סמיכה (an עשה), because it was after the הפרשה. Rava answers that in the case of סמיכה, until he actually shechts the korban, בעמוד וסמוך קאי – he is still subject to the command, “Arise and perform semichah.” Thus, he does not violate it until after he actually shechts without doing semichah, לאחר שחיטה לא קא מיבעיא לן – and a violation after shechitah is not a question to us, because it is certainly not atoned for by the korban.

The Gemara suggests another proof from a Baraisa in which Rebbe Shimon explains the atonement of the שעירי עצרת – two he-goats brought on Shavuos (the first brought with the שתי הלחם, and the second as part of the מוסף). They both atone for טומאת מקדש וקדשיו – tumah violations of the Mikdash and its holy things (i.e., meat of korbanos), but after the first שעיר already atones for it, what is the purpose of the second שעיר? He explained that it atones for tumah which occurred between the first and the second (i.e., on Shavuos, after the first was sacrificed). This proves that a korban can atone for transgressions after הפרשה!? The Gemara suggests that the second שעיר atones for transgressions between the הפרשה of the first and the second (before Shavuos), in a case when they were designated at different times. However, the Gemara objects to limiting this korban’s entire purpose to such a specific circumstance, and instead suggests that לב בית דין קמתנה עליהן – Beis Din’s mind stipulates about [קרבנות צבור] that their designation is pending until their actual הקרבה, so any violation beforehand precedes its confirmed "הפרשה". Ultimately, this explanation is refuted, and Tosafos says we accept the forced explanation that the korban’s purpose is for where they are designated at different times.