Chullin 10

Ritual slaughter requires cutting an animal’s throat — specifically, its windpipe and gullet — with a sharp knife that has no imperfections. On today’s daf, the Gemara considers what we are supposed to do if a flaw in the blade is discovered after the fact:

With regard to one who slaughters an animal with a knife that was afterward found to be notched:
 
Rav Huna says: Even if he broke bones with the knife all day, the slaughter is not valid, as we are concerned that perhaps the knife became notched on the hide of the neck. 
Rav Hisda says: The slaughter is valid, as perhaps it was on the bone that he broke with the knife.

The concern, of course, is that the knife had a notch while being used to slaughter the animal. Rav Hisda rules the slaughter valid since it is reasonable to assume that the knife became notched when it struck the bones of the spine after cutting through the windpipe and gullet — that is, after the ritual is complete. Not so, says Rav Huna: Even if the knife was later used to cut bones “all day,” making it likely that the notch developed after the slaughter, the slaughter is invalid based on the possibility, however slight, that the notch developed from contact with the animal’s hide, just before it severed the windpipe and gullet.

Yesterday we learned that Rav Huna believes that the default status of an animal is prohibited, that is, we are not permitted to eat it until we are sure that it was slaughtered correctly. In this case, the discovery of the notch on the knife creates an uncertainty about the slaughter. Without further evidence that the knife was intact before it was put to use, we are unable to set aside the animal’s presumptive status; its meat is prohibited as a result.

Rav Hisda thinks differently:

A bone certainly notches the knife, but with regard to hide, it is uncertain whether it notches the knife and uncertain whether it does not notch it. This is a case of certainty and uncertainty, and the principle is that an uncertainty does not override a certainty.

In other words, we know that bones chip knives, but we are not sure that an animal’s hide can do the same. Furthermore, our certainty that bones can damage knives is more significant than our uncertainty about whether the animal’s hide caused the notch. The certainty “overrides” the uncertainty and, accordingly, the slaughter is valid and the meat is permitted.

While it is not always the practice to do so, the Gemara makes a ruling about this dispute. We follow Rav Huna in cases where the knife was not used to break a bone after the slaughter was complete, and we follow Rav Hisda in cases in which it was. The Gemara’s logic? If the knife was later used to break a bone, we have a likely cause of the notch and are comfortable following the more lenient Rav Hisda. But when the knife was not used to cut bones after the slaughter, the source of the notch remains a mystery. Out of an abundance of caution, we follow Rav Huna’s more restrictive position.

The deeper issue in this debate is how certain we must be that a ritual slaughter was performed correctly in order to validate it. Do we demand 100% certainty, or are there instances where we can make exceptions? And if we allow ourselves to make exceptions, under what conditions? 

Read all of Chullin 10 on Sefaria.

This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on May 10, 2026. If you are interested in receiving the newsletter, sign up here.