The Gemara (Pesachim 108a) rules:

פרקדן לא שמיה הסיבה הסיבת ימין לא שמה הסיבה ולא עוד אלא שמא יקדים קנה לוושט ויבא לידי סכנה

Lying prone is not called leaning. Leaning right is not called leaning. Furthermore, the trachea might come before the esophagus and he will come to a danger.

Rashbam ad. loc. first proposes that the issue of danger is when one is lying prone, but he then proposes a second understanding (followed l'halacha by the Mishnah Berurah 472:10 with a practical difference for lefties at the Seder) in which this last line refers to the second clause, regarding leaning right:

דושט הוי על (דרך) ימין ונפתח הכובע שעל פי הקנה מאיליו כשהוא מטה כלפי ימין ואם יכנס בו המאכל הרי סכנה שאין אוכלין ומשקין נכנסין אלא דרך הושט

The esophagus is to the right, and when one leans to the right the epiglottis will open from the windpipe. If food enters [the windpipe], there will be a danger, for food and drink only pass through the esophagus.

How can Rashbam say that the trachea is to the left and the esophagus to the right, when the trachea is to the front, and the esophagus is to the back? Wikipedia has a nice diagram, but you can tell for yourself by pressing gently on the front of your throat: the hard rings you'll feel are the outer lining of your trachea.

How can Rashbam posit that this line refers specifically to leaning to the right, when it contradicts very obvious anatomical facts?

  • I have other problems with the Mishnah Berurah, but I'd like to figure out anatomically what he's referring to before I discuss my other issues, which are physiological in nature and made much more difficult by the presence of four cups of alcohol.
    – DonielF
    Commented Mar 23, 2020 at 23:32
  • 3
    Are you specifically looking for an answer other than that he was not aware of the anatomical facts? Note the Radvaz already raises the anatomical question on the Rashbam.
    – Alex
    Commented Mar 24, 2020 at 0:06
  • @Alex Yes. The relevant anatomical facts are just too obvious for me to accept that he was not aware of them. If the Radvaz gives an answer besides Rashi fits better, please share!
    – DonielF
    Commented Mar 24, 2020 at 2:50

1 Answer 1


I'm not sure this quite answers your question, but Radvaz (3:584 (1012)) does seem to question Rashbam's anatomical facts, and says something that might be considered an answer:

ועוד ראיתי כי הסימנים שוכבין זה על זה ולא ידעתי אם סימני אדם נשתנה

Depending on how you read this, he could be entertaining the possibility that the anatomical facts had changed over time. What might have been anatomically true in the times of Rashbam (or Chazal) may have no longer been true.

  • 2
    I'm reading the line without any context, but I would have read סימני אדם נשתנה (human signs are different from animals signs), not humans changing over time (maybe this is what you mean by "depending on how you read this")
    – b a
    Commented Mar 24, 2020 at 14:51
  • @ba That is precisely what I meant by “depending on how you read it”.
    – Alex
    Commented Mar 24, 2020 at 14:52
  • @ba A) Why would Chazal be discussing animal anatomy in this context? B) As far as I can tell, bovine, equestrian, canine, and human pharynxes (couldn't find anything on other animals in my quick search), while all distinct from one another, all share that the trachea is in front and the esophagus in back. Chazal surely knew how animal throats are structured given their role in Shechitah.
    – DonielF
    Commented Mar 24, 2020 at 14:58
  • @DonielF The point is that it’s not clear if the ראיתי was on an animal or a person.
    – Alex
    Commented Mar 24, 2020 at 15:00
  • @Alex cc ^^. Extending this further, with such diversity among different creatures, which all have different methods of eating (chewing cud vs. not) and all have different diets (carnivorous, herbivorous, omnivorous), yet they all have the exact same structure with regards to the trachea and esophagus makes it difficult for me to accept that this changed over time in humans specifically. If ראיתי refers to animals, and he's not clear on if humans are different...again, just push gently on the front of your throat. It's not too hard to check.
    – DonielF
    Commented Mar 24, 2020 at 15:00

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .