לרפואת האדמו"ר ר' יצחק מנחם בן גיטל מירל בריינדל לאה בתוך שאר חולי ישראל
The mishna says that if one knows the essence of Shabbos and performed many melachos on many Shabbosos [because he thought it was a weekday] he is liable to a chatas for every Shabbos. Rashi explains : אע"פ שלא נודע לו בינתיים אמרינן ימים שבינתיים הויין ידיעה לחלק שאי אפשר שלא שמע בינתים שאותו היום שבת היה אלא שלא נזכר במלאכות
Even though he didn't find out during the week that he had sinned, we say that the interim weekdays are considered "knowledge" to separate [the sins] because it is inconceivable that he didn't hear during the week that it had been Shabbos. He just didn't remember that he had performed melacha on that day.
Tosfos asks:
וקשה לה"ר אליעזר, דאמר בגמ' קצר וטחן כגרוגרת בשגגת שבת וזדון מלאכות וחזר וקצר וטחן כגרוגרת בזדון שבת ושגגת מלאכות כו' אלמא אע"פ שנודע לו קודם קצירה אחרונה שאותו יום שבת הוא, דהא בזדון שבת קצר וטחן, אפ"ה לא הויא ידיעה וחשיב העלם אחד כיון שלא נודע לו שחטא שהרי סבור שהמלאכה מותרת. וטעמא משום דכתיב או הודע אליו חטאתו שהיה לו ידיעת החטא
Peirush-Ally: The gemara says later [70b] on that if a person both harvested and grounded on Shabbos, while forgetting that it was Shabbos, but knowing that these were forbidden labors on Shabbos, he is only liable to one chatas [for the root of the sin was one thing - he forgot Shabbos]. If he then does it again but this time he knows that it is Shabbos but forgot that these were melachos, he must bring 2 chataos [for his sin was rooted in forgetting two melachos]. If he found out about the first mistake [forgetting Shabbos and performing the two melachos] and separated a chatas and then found about about the second mistake [forgetting that these were melachos] the halacha is that the chatas he separated covers both mistakes because the kappara on the first harvesting covers the second harvesting and the kappara on the first grinding covers the second - קצירה גוררת קצירה וטחינה גוררת טחינה. Now according to Rashi this must have all happened on one Shabbos because if it had happened on two separate Shabbosos then he would have to bring separate chataos because the interim days are considered ידיעה לחלק - knowledge that separates the sins.
It nevertheless emerges from the gemara that even though he knew before the second mistake that it was Shabbos that day [because he then performed the two melachos with the knowledge that it was Shabbos but thinking that they were permitted] he is only liable to bring one chatas and we don't say that he had ידיעה לחלק. This presents a serious problem for Rashi because we see that knowledge of the fact that it was Shabbos is NOT enough and the person must actually know that he sinned. The reason is that the pasuk says about the chiyuv chatas או הודע אליו חטאתו - he knew about his sin. He must know that he sinned and retroactive knowledge of the correct calender day of Shabbos does not suffice in order to be liable a korban.
There is much more to say and I hope we say. But we will suffice with this in the meantime. Blog posts can't be too long. We live in the Facebook generation. People who want long pilpulim are invited to my house for a shiur. People who don't are invited anyway....:-)
