Resources for Kesubos daf 5

1.     The גמרא says that if someone is בועל בעילת מצוה on מוצאי שבת there is a concern of שמא ישחט בן עוף. The גמרא then asks that if we are really concerned about this then we shouldn’t allow יום הכיפּורים to fall out on a Monday because someone may start preparing on מוצאי שבת for the meal on ערב יום הכיפּורים. The גמרא answers that the person in that case has plenty of time. רש"י in ד"ה ידחה explains that the סעודה of ערב יום הכיפּורים isn’t until the morning so there is no pressure to shecht on שבת. The ערוך השלחן in סימן תר"ד (and others) say that this רש"י is an explicit proof that the מצוה of eating on יום הכיפּורים is only in the day time and not at night. However, the ספר עטרת שמואל brings from ר"א גורביץ that רש"י is only saying there is no חיוב סעודה until the daytime. However, there may be a חיוב אכילה even at night. His proof is that when the שולחן ערוך quotes the חיוב סעודה in סימן תר"ד, the גר"א brings the citation from our רש"י in כתובות and not from the seemingly more relevant גמרא in ברכות דף ח where it says that there is a מצוה to eat on ערב יום הכיפּורים. It must be that our רש"י is specifically a proof for a חיוב סעודה (where שמא ישחוט בן עוף is relevant) but there may be a מצוה to eat even at night.

2.     The גמרא discusses being בועל מתחילה בשבת which may involve making a wound. There is an important מחלוקת ראשונים about what the איסור is. רש"י in שבת דף ק"ז says that the איסור is צובע. תוספות here in ד"ה דם asks that רש"י’s explanation doesn’t seem to fit our גמרא since there is no coloring of the skin occurring. The תוספות הרא"ש also asks that there would be no difference between מיפקד פּקיד and חיבורי מיחבר if the issue was צובע. The פּני יהושע there in שבת explains that רש"י only meant the issue was צובע in  מסכת שבת because the discussion there is making an animal black and blue where no blood actually comes out, but רש"י would agree the issue here is not צובע. ר"ת suggests the איסור is נטילת נשמה meaning the loss of blood is considered taking the person’s נשמה to an extent since “הדם הוא הנפש”. The רמב"ם  in הלכות שבת פּרק ח׳ הל׳ ז says that the איסור is מפרק which is a תולדה דדש (extraction of something from where it naturally grew). The מנחת חינוך in מלאכת שבת מלאכת דש אות ג asks that if the issue is מפרק then what difference does it make if it is מיפקד פּקיד or חיבורי מיחבר? If you smoosh a חלזון to get its blue dye for תכלת the גמרא says it is חייב משום מפרק even though the blood is certainly מיפקיד פּקיד! So why would מיפקיד פּקיד be a היתר for דש? He leaves it as a question. The חתם סופר here has a beautiful explanation of the גמרא and רמב"ם . He asks what was the גמרא’s question about מיפקד פּקיד and חיבורי מיחבר was anyway—is this a מציאות question? He explains everyone agrees about the מציאות—the blood is connected to the ביתולין like water in a sponge. The question is if that is considered מיפקד פּקיד or חיבורי מיחבר. He explains that the classic מפרק is removing juice from a grape. However, if you simply pull back the skin and juice comes out, it isn’t מפרק. That’s just opening the door. מפרק  requires that you need to smoosh it. Similarly, the question here is that if the blood is considered מיפקיד פּקיד then we are saying it’s simply opening the door. If it’s considered חיברי מחבר then we view it as squeezing and it would be מפרק.

It is important to note that the רמב"ם  in הלכות אישות פּרק י׳ הל׳ י"ד holds that there is also an איסור of שמא ישחוט בן עוף. The ר"ן explains that according to the רמב"ם  the discussion in our גמרא if you can be בועל בתחילה בשבת is only when the meal was already prepared before שבת.