Today we continue the intricate discussion of how one examines an animal that has been slaughtered to determine if it is a treifa, and therefore unkosher. On today’s daf, we learn a new technique:
Rav Shimi bar Hiyya says: One may compare perforations in the intestines.
Rashi helps us understand what this means: If the intestine of a slaughtered animal is found to be perforated, and it is unclear whether the perforation occurred before or after the slaughter (which would determine whether or not the meat is kosher), this can be determined by a test: Making a second perforation in the intestines allows us to compare the two injuries. If the two perforations look similar, it’s safe to assume the first puncture occurred after slaughter, and the animal is kosher. If they look significantly different, the first puncture is assumed to have happened before the animal was slaughtered. The animal is deemed a treifa and cannot be eaten.
As has occurred frequently in this chapter, we’re given a story in which this test is, well, put to the test:
There were certain perforated intestines that came before Rava. Rava compared them, but they were not similar. Rav Mesharshiyya, his son, came and rubbed the new perforations, and they were similar.
Rava said to him: From where did you know to do this?
Rav Mesharshiyya said to him: I reasoned: How many hands rubbed these earlier perforations before they came before the master?
Rava said to him: My son is as wise in matters of treifot as Rabbi Yohanan.
In accordance with Rav Shimi bar Hiyya, Rava used the perforation comparison test. At first glance, the perforations were dissimilar, suggesting the intestines he’d been asked to check were not kosher. However, his son came to the rescue: Rav Mesharshiyya rubbed the new perforations a bit and, suddenly, they looked identical to the older perforations! He explained: The intestines Rava was asked to check had already been handled by many hands, so it’s logical that such wear might change the appearance of the perforations. Since the new perforations looked similar once they were rubbed, simulating that handling, we can conclude that the perforations occurred after slaughter. Rava ecstatically commended his son’s technique, which saved perfectly good meat from being declared unkosher.
Apropos the mention of Rabbi Yohanan, the Gemara notes that this method isn’t limited to intestines:
Rabbi Yohanan and Rabbi Elazar both say: One may compare perforations in the lung. Rava said: We said this only when the two perforations are on the same side of the lungs. But one may not compare perforations from one side to the other side.
Rabbi Yohanan and Rabbi Elazar think this same method of comparison can be used when checking lungs. Interestingly, Rava, who clearly uses this method for intestines, is somewhat circumspect in the case of lungs — limiting the test to perforations on the same side of the organ. Yet, immediately following Rava’s comment, the stam, the anonymous voice in the Gemara, follows up:
And the halakhah is: One may compare even from one side to the other side, and even from a small animal to another small animal, or from a large animal to another large animal. But not from a large animal to a small animal, and not from a small animal to a large animal.
The final halakhah is far more permissive. Not only can one compare the two sides of the lung, but one can even compare the lungs of two different species! This test turns out to be widely applicable, with the only noted limitation coming from the classification of animals into “small” and “large.” So while one can compare a sheep lung to a goat lung, one shouldn’t compare a sheep lung to a cow lung. Nonetheless, this final ruling is far more expansive, giving the rabbis far greater ability to permit animals that did not actually have defects but had been roughly handled post-slaughter.
Read all of Chullin 50 on Sefaria.
This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on June 18, 2026. If you are interested in receiving the newsletter, sign up here.
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