We’re in the midst of a lengthy discussion about intermingling. Starting with the mishnah back on 71a, the Gemara has been considering the implications if a forbidden, yet indistinguishable item —animal, fruit, or something else — is mixed in with what’s intended to be a proper sacrifice. How do you separate it out? Is the whole batch tainted? While the specifics differ from situation to situation, the rabbis tend to hold the line on a relatively strict standard: that even one disqualified item can ruin an entire group of legitimate inventory.
Today, our daf reviews compound uncertainty (sefeik sefeika), where some, but not all, of the intermingled items fall into another collection, and there’s double doubt as to which items are prohibited and which are acceptable. The sugya is long, so we don’t have space to go into the entire argument, but let’s take a look at what’s going on, starting with this example:
Rav says: A ring used in idol worship that was intermingled with 100 permitted rings, and then 40 of them became separated to one place, and the other 60 became separated to another place, if one ring from the group of 40 became separated (and then became intermingled with other rings), it does not render them prohibited. But if one ring from the other 60 (became separated from its group and became mixed with other rings), it renders them prohibited.
We know that there’s a very strong prohibition on anything associated with idol worship, and that even deriving benefit from such an item is often barred. Here, a forbidden ring falls into a collection of 100 rings, and the intermingled group is divided into a group of 40 and a group of 60. (Technically, there’s a missing ring here, but let’s run with Rav’s thinking for now.) If a ring from the group of 40 gets intermingled with a new group, all’s well, but if one of the 60 gets intermingled, we have a problem.
What’s the logic here?
The prohibited ring is in the majority. One ring from the group of 60, we should also say that the prohibited ring is in the majority. Rather, (Rav’s statement was as follows): If all 40 became separated to one place, the 40 rings do not render those other rings prohibited. If all of the 60 rings became separated to one place, the 60 rings render those other rings prohibited.
Rav seems to assume that when a group of contaminated rings is divided, the forbidden ring is always among the majority. Which is a sound assumption, on the theory that the more rings, the better the odds that the contaminated ring is among them. However, according to that logic, if you took one from the group of 60 rings, the odds of finding the tainted ring (one in 60) are worse than if you took from the other group (one in 40). However, that’s not the conclusion Rav reaches. Instead, the Gemara clarifies: Rav’s comments apply when we’re talking about the 60 rings as a whole, not each individually.
Rav’s conclusion seems lenient when compared to that of Shmuel, as Rav Yehuda relates:
When I said this ruling in the presence of Shmuel, he said to me: Disregard in the case of idol worship, as its uncertainty and its compound uncertainty are prohibited forever
This gets back to what we learned in earlier tractates: Idol worship is really bad, so the rabbis want to make sure we stay far away from it. As a result, Shmuel teaches that even the group of 40 rings is prohibited if one ring connected with idol worship fell into them. To him, compound uncertainty is still uncertainty.
The debate continues, with Rabbi Shimon pushing back against Shmuel’s strictness. By the time we get to the Mishneh Torah, Maimonides states the general proposition: “When there is a doubt whether an object is connected to idol worship or not, it is forbidden. If, however, that doubt is questionable (i.e., compound uncertainty), it is permitted,” a sentiment largely echoed by the Shulchan Aruch.
None of this should be taken as license to be careless with what we intend to offer as sacrifices. After all, it’s better to be free from doubt entirely and to enjoy the benefits of the entire stock we’ve worked hard to amass. But in the event there’s a mistake, we can rest assured that compound uncertainty gives us a little leeway in making do.
Read all of Zevachim 74 on Sefaria.
This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on November 27, 2025. If you are interested in receiving the newsletter, sign up here.
