Resources for Yevamos daf 68
1. The משנה says that a ספק בן ט׳ שנים ויום אחד who is בא על האשה makes her פּסולה to eat תרומה. רבא explains that this refers to a nine year old boy who is פּסול לקהל. תוספות in ד"ה רישא asks why we don’t say that 1) the woman has a חזקת כשרות and 2) the boy has a חזקה that he is less than nine years old until proven otherwise? He answers that we are discussing a case where at the time the question came before us the boy was already more than nine years old. Therefore, since the original חזקה now has a ריעותא, we cannot use it. There are several important questions on תוספות. First, he seems to have only answered one of the two questions. He explained why the חזקה of the boy wouldn’t work but he doesn’t explain why the woman’s חזקת כשרות doesn’t help? Second and more fundamentally, don’t we say that a חזקה of what always was (חזקה דמעיקרא) beats a חזקה of what currently is (חזקה דהשתא)? For example, the משנה in מקוואות says that if a מקוה was known to have 40 סאה and now it is found to have less than 40 סאה, then as far as the מקוה itself is concerned we would assume it had 40 סאה until the last minute even though right now it doesn’t. So why don’t we say here as well that we should assume the boy was nine until the last minute? Lastly, תוספות ישנים here answers תוספות’s question by saying that the child being less than nine years old is a חזקה העשויה להשתנות and is not a valid חזקה. In other words, a חזקה that inherently will eventually change is not a valid חזקה. Why didn’t תוספות answer that? The מהרי"ט in שו"ת מהרי"ט חלק א׳ סימן י"א answers all these questions. He explains that תוספות agrees that the woman has a חזקת כשרות and the child does not have a חזקה because it is עשויה להשתנות. However, had they come to us when the child was still a ספק פּחות מבן ט we would have assumed that the boy is below nine because of her חזקה. In other words, her חזקת כשרות would have informed our view of him and told us to view him as being בחזקת less than nine. However, now that they have come to us when he is already nine, her חזקת כשרות has been impacted and hurt and ממילא we can no longer assume he was less than nine. The שב שמעתתא in שמעתתא ג פּרק י disagrees with the notion that a חזקה העשויה להשתנות is not a good חזקה and says that this is in fact why תוספות didn’t give that answer like the תוספות ישנים did. In פּרק י"ג he explains that it is true that we normally say that a חזקה דמעיקרא beats a חזקה דהשתא. However, our תוספות is different in that here we are specifically talking about תרומה and תרומה is an exception where we are even מחמיר for a חזקה דהשתא (where it is a חומרא). The רש"ש has a third approach and explains that תוספות here holds like the ט"ז in יו"ד סימן שצ"ז ס"ק ב which is in between the above mentioned שיטות. He says that תוספות would say that while a חזקה העשויה להשתנות is a good חזקה, it is only until it actually changed. Once it changes (in our case where he already turned nine) then we cannot use it retroactively anymore.
2. The גמרא says that if a woman is נבעלת to a עמוני ומואבי etc. she becomes פּסול as it says ובת כהן כי תהיה לאיש זר וכו׳. The קובץ הערות in סימן מ"ד אות י brings a מחלוקת ראשונים as to what type of פּסול she gets. תוספות on דף ט"ו ע"ב ד"ה מה לאלמנה as well as רש"י on דף ע ד"ה נשיהם say that she becomes a חללה. תוספות explains that even though a חללה is normally only a product of an איסור that is specific to כהונה, these are specifically learned from a פּסוק. The רשב"א on דף ע׳ disagrees and say that she becomes a זונה.
Rabbi Millman's Marei Mekomos Halacha
New Daf Hashavua newsletter - Shavua Matters
Rabbi Mordechai Papoff - English Topics
Rabbi Yaakov Blumenfeld - Shakla Vetarya
Rabbi Yechiel Grunhaus - Points to Ponder