Central to the sacrificial system is the altar where sacrifices were offered. Given the volume of sacrifices that were offered daily, it makes sense that from time to time the altar would come to be in a state of disrepair. On today’s daf we learn that any offerings that were made on a damaged altar are disqualified:
Rav says: An altar that was damaged, all sacrificial animals that were slaughtered there are disqualified. We have a verse (as the source for this law) but we have forgotten it.
Rav remembers the rule, but not its source. Not to worry, however, because Rav Kahana, upon arriving in Israel from Babylonia, recovers the missing information:
When Rav Kahana ascended, he found Rabbi Shimon, son of Rabbi Yehuda HaNasi, saying in the name of Rabbi Yishmael, son of Rabbi Yosei: From where is it derived that an altar that was damaged, that all sacrificial animals that were slaughtered there are disqualified?
As it is stated: “An altar of earth you shall make for Me, and you shall slaughter upon it your burnt offerings and your peace offerings [shelamekha]” (Exodus 20:21). When complete [shalem], but not when it is damaged. This is the verse that eluded Rav.
The Hebrew word for peace offering comes from the same root as the word for complete: shin, lamed, mem. This allows for a creative interpretation of Exodus 20:21 — the peace offering, and all others too, must be made on an altar that is complete, i.e. undamaged.
In response to Rav’s sourceless ruling, the Gemara could have chosen, as it does in many other situations, to ask, “From where are these words derived?” and then proceed to provide the verse and its midrashic explanation. Instead, it reports Rav’s memory lapse, preserving the moment in the talmudic record for all time. One could argue that, in doing so, it tarnishes Rav’s reputation and calls him out unnecessarily. What might motivate the editors of the Talmud to do so?
The Talmud is not shy about reporting the limitations of the rabbis who populate its pages, including when their memory fails them. For example, on a number of occasions we read about Rav Yosef being unable to recall a teaching that his students remember learning directly from him (see Eruvin 10a and Bava Metzia 8). In doing so, the Talmud reminds us that the rabbis are human and confront the challenges of memory loss just like the rest of us.
Or perhaps Rav was not one to forget an important detail, especially the verse upon which his teaching was based, and this incident stood out in the memory of his students — so much so that the incident became so associated with the rule that it too became embedded in the talmudic tradition. Or perhaps they wanted to give credit to Rav Kahana for filling in the missing knowledge and it did not occur to them to find a way to do so without first explaining why it was missing in the first place. Or perhaps they were unaware of how reporting this incident may have been insensitive to Rav and did not think twice about sharing it.
But maybe their motivation was something else altogether: a way for them to remind us of why the Talmud was written down in the first place. The Talmud, after all, is part of the Oral Torah. It was initially memorized instead of being recorded in writing as a way to distinguish it from the Written Torah. God’s words merit being preserved in writing; our words are preserved in our memories. The move to record the Oral Torah in writing was in response to Roman persecution, which banned the teaching and learning of Torah. Fearing that the material would be lost, the rabbis committed to gathering, organizing, and canonizing their decisions — the Mishnah is the result of this project.
As the study of Mishnah became the focus of the rabbinic academies, the discussions about it were at first committed to memory. But as the incident reported on today’s daf reminds us, this was not a perfect system. Even the greatest of scholars might fail to recall a key detail. And, given the expansive nature of the rabbinic conversations about the Mishnah, the burden of remembering them was certain to grow exponentially. In order to preserve that which took place in the rabbinic academy, a written record was required. Seen in this light, preserving the story about the time that Rav forgot the verse was not meant to cast a light on his moment of weakness. Rather, it was to remind us of how, or why, the Gemara came to be written down.
Read all of Zevachim 59 on Sefaria.
This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on November 12, 2025. If you are interested in receiving the newsletter, sign up here.
