According to the Torah, to be kosher a fish must have both fins and scales. Lacking either means the fish in question is forbidden. A beraita on today’s daf makes a related scientific observation:
Any fish that has scales certainly has fins, but there are fish that have fins and do not have scales.
The beraita informs us that if a fish has scales it definitely has fins, so when checking a fish to determine if it is kosher, it suffices to check for scales. This leads the Gemara to ask why the Torah bothered to mention fins at all:
Since we rely only on scales to deem a fish kosher, let the Merciful One write only “scales” as the sign of a kosher fish and not write “fins” at all!
There is no need for the Torah to tell us that a kosher fish must have fins; it would have been sufficient for it to require only scales. So why the extra word? Here is the first proposed answer:
If the Merciful One had written “scales” (kaskeset), and had not written “fins” (senappir), I would reason: “What is kaskeset? It is fins.” And I would thereby come to permit even non-kosher fish. Therefore, the Merciful One stated: “fins and scales.”
Even in the time of the rabbis, certain words in the Torah were already archaic and unfamiliar. The word for scales, kaskeset, is one example. Just as scholars do today, the rabbis inferred the meanings of these words from context. In the Torah, senappir and kaskeset always appear together in the laws of kosher fish. Had the Torah mentioned only one, its meaning might have been ambiguous, potentially leading people to believe kosher fish require fins but not scales—and causing them to consume forbidden species. Therefore, the Torah includes both words as a safeguard, even though explicitly mentioning fins is technically redundant since all fish with scales possess them.
The Gemara is not so sure about this argument. It cites 1 Samuel 17:5, from the story of David and Goliath, which also uses the word in question: “And he (Goliath) was clad with a coat of scale armor (kaskasim).” This verse, the rabbis argue, makes the meaning of kaskeset clear. There is no way that we would erroneously think it means “fins.” And so, we are back to our original problem: The Torah does not need to list fins as a required characteristic of a kosher fish; kaskeset (scales) would suffice. So why the extra word?
To resolve this question, the Gemara changes tactics and cites a teaching of Rabbi Abbahu (or perhaps a teacher from the school of Rabbi Yishmael) that is based on Isaiah 42:21: “The Lord was pleased, for God’s righteousness’ sake, to make Torah great and glorious.” Rabbi Abbahu suggests that the Torah’s flourishes are included for aesthetics, adding beauty to the Torah and making it “great and glorious.” Applied to today’s discussion, this suggests that by utilizing the phrase “fins and scales” instead of “scales” alone, we end up with a more beautiful verse. This satisfies the Gemara and it moves on to a new topic.
Today’s discussion is driven by the common rabbinic assumption that every word in the Torah is necessary because it adds meaning. The rabbis do not usually accept the idea that words have been added simply for beautification — to make a phrase pretty. Rabbi Abbahu’s teaching, that the word “fins” is essentially decorative, runs counter to this trend. Why would the rabbis accept his unusual argument? Is it simply because it solves their problem of explaining why the Torah includes the redundant requirement for kosher fish to have fins? This is possible, but not fully satisfying to me. As I thought more about what Rabbi Abahu said, I was reminded that the predominant mode of biblical interpretation in the Talmud is not the only way to read and understand the Torah. And perhaps, by giving Rabbi Abbahu the last word in this conversation, the editors of the Talmud are reminding us of this as well.
Even in the time of the rabbis, certain words in the Torah were already archaic and unfamiliar. The word for scales, kaskeset, is one example. Just as scholars do today, the rabbis inferred the meanings of these words from context. In the Torah, senappir and kaskeset always appear together in the laws of kosher fish. Had the Torah mentioned only one, its meaning might have been ambiguous, potentially leading people to believe kosher fish require fins but not scales—and causing them to consume forbidden species. Therefore, the Torah includes both words as a safeguard, even though explicitly mentioning fins is technically redundant since all fish with scales possess them.
The Gemara is not so sure about this argument. It cites 1 Samuel 17:5, from the story of David and Goliath, which also uses the word in question: “And he (Goliath) was clad with a coat of scale armor (kaskasim).” This verse, the rabbis argue, makes the meaning of kaskeset clear. There is no way that we would erroneously think it means “fins.” And so, we are back to our original problem: The Torah does not need to list fins as a required characteristic of a kosher fish; kaskeset (scales) would suffice. So why the extra word?
To resolve this question, the Gemara changes tactics and cites a teaching of Rabbi Abbahu (or perhaps a teacher from the school of Rabbi Yishmael) that is based on Isaiah 42:21: “The Lord was pleased, for God’s righteousness’ sake, to make Torah great and glorious.” Rabbi Abbahu suggests that the Torah’s flourishes are included for aesthetics, adding beauty to the Torah and making it “great and glorious.” Applied to today’s discussion, this suggests that by utilizing the phrase “fins and scales” instead of “scales” alone, we end up with a more beautiful verse. This satisfies the Gemara and it moves on to a new topic.
Today’s discussion is driven by the common rabbinic assumption that every word in the Torah is necessary because it adds meaning. The rabbis do not usually accept the idea that words have been added simply for beautification — to make a phrase pretty. Rabbi Abbahu’s teaching, that the word “fins” is essentially decorative, runs counter to this trend. Why would the rabbis accept his unusual argument? Is it simply because it solves their problem of explaining why the Torah includes the redundant requirement for kosher fish to have fins? This is possible, but not fully satisfying to me. As I thought more about what Rabbi Abahu said, I was reminded that the predominant mode of biblical interpretation in the Talmud is not the only way to read and understand the Torah. And perhaps, by giving Rabbi Abbahu the last word in this conversation, the editors of the Talmud are reminding us of this as well.
Read all of Chullin 66 on Sefaria.
This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on July 4, 2026. If you are interested in receiving the newsletter, sign up here.
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