We’re going to focus on two aspects of the complicated argument on today’s daf. The first is about content: As we will soon learn, being in a state of acute mourning limits what sacrificial rites a priest can perform. The second, and perhaps more interesting, is about derivation of law: Today the rabbis express concern that certain rabbinic techniques of interpretation are so powerful they can “prove” wrong conclusions. Let’s dive in:
The mishnah teaches that if an acute mourner collects the blood of an offering, the offering is disqualified.
Rava says: They taught this only with regard to an individual’s offering. But with regard to a communal offering, a rite performed by an acute mourner does effect acceptance. One can derive this by kal va’homer inference from ritual impurity. Just as a priest is prohibited from performing rites in a state of ritual impurity, whose general prohibition was not permitted in the case of a high priest performing rites for an individual’s offering, was nevertheless permitted in the case of an ordinary priest performing rites for a communal offering; then so too, with regard to the prohibition against performing rites while in a period of acute mourning, whose general prohibition was permitted in the case of a high priest performing rites for an individual’s offering, is it not right that this prohibition was permitted in the case of an ordinary priest performing rites for a communal offering?
Those long sentences don’t translate easily to readable English, so let’s walk through the logic, which rests on the interpretive technique known as kal va’homer (in English, via Latin, it’s called an a fortiori inference): A priest who’s an onen, an acute mourner, cannot sacrifice an offering on behalf of an individual. If he does, it’ll be disqualified. But can the priest in mourning make a sacrifice on behalf of the community? According to Rava, yes. He derives this conclusion from an analogy to the laws about sacrifices performed in a state of ritual impurity. No impure priest, be it an ordinary priest or the high priest, can sacrifice an offering on behalf of an individual. However, in some cases an impure priest can sacrifice a communal offering.
As a general rule, the restrictions connected with acute mourning are more lenient than those associated with impurity. How so? A high priest who is an acute mourner is permitted to sacrifice any offering, be it individual or communal. Given that impurity is more restrictive in the case of sacrifices on behalf of an individual, in that even the high priest can’t offer them while impure, and nonetheless an impure priest can make a communal offering, we conclude that all the more so in the case of acute mourning, which is more lenient about sacrifices offered on behalf of individuals, should a priest who’s an onen be able to make a communal offering. Conclusion: Through kal va’homer, we learned that a priest who is in acute mourning can nonetheless perform communal sacrifices.
While Rava makes a compelling case that a priest in acute mourning should be able to make communal offerings, another rabbi immediately tears it apart:
Rava bar Ahilai objects to this: The performance of rites in a state of acute mourning should not be permitted in the case of a high priest performing rites for an individual’s offering, by kal va’homer inference: And just as the prohibition against performing rites in a state of ritual impurity, whose general prohibition was permitted in the case of an ordinary priest performing rites for a communal offering, was not permitted in the case of a high priest performing rites for an individual’s offering; then so too, with regard to the prohibition against performing the rites during a period of acute mourning, whose general prohibition was not permitted in the case of an ordinary priest performing rites for a communal offering, is it not right that this prohibition should not be permitted in the case of a high priest performing rites for an individual’s offering?
Let’s explain this logic as well. We know that an impure priest is able to perform rites for a communal offering, even though they cannot do so for an individual offering. Despite this allowance, even the high priest isn’t allowed to sacrifice an individual offering while impure. If even for impurity, which has this explicit leniency when it comes to communal offerings, the high priest isn’t given permission for an individual offering, then for acute mourning, which is more stringent in that there’s no permission for an ordinary priest who’s an acute mourner to offer even a communal sacrifice, shouldn’t it be all the more so true that a high priest who’s a mourner can’t offer an individual offering? And yet we know this is not the case!
What just happened? Rava bar Ahilai just demonstrated that kal va’homer, while powerful, can be unreliable. While Rava used kal va’homer to reach one conclusion, Rava bar Ahilai used it to reach the opposite conclusion — one that we know is incorrect. Rava bar Ahilai is not doing this to make an argument for an incorrect law, but rather pointing out the fallibility of kal va’homerarguments.
If you read the daf for yourself, you can see that Rava bar Ahilai goes on to demonstrate two other false conclusions one could make from this set of facts using a similar “logical” argument. Thus, he proves over and over that kal va’homer can be used to derive incorrect law.
Does this mean the rabbis should stop using kal va’homer? Not at all. Indeed, it is used frequently throughout the Talmud. But like any tool, it can be used to build or to tear down. It should not be used indiscriminately.
Read all of Zevachim 16 on Sefaria.
This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on September 30, 2025. If you are interested in receiving the newsletter, sign up here.
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