“…From all that are in the water, you may eat any (living creature) that has fins and scales, whether it lives in the waters, seas, or rivers; you may eat only these…” – Vayikra 11:9

אֶת זֶה תֹּאכְלוּ מִכֹּל אֲשֶׁר בַּמָּיִם כֹּל אֲשֶׁר לוֹ סְנַפִּיר וְקַשְׂקֶשֶׂת בַּמַּיִם בַּיַּמִּים וּבַנְּחָלִים אֹתָם תֹּאכֵלוּ – ויקרא יא, ט

Two distinctive features identify a kosher fish: a layer of scales that protects its body, and a set of fins that it uses to swim.

Fish are symbolic of Torah scholars; like fish, which are always underwater, the scholars are constantly immersed in the life-giving waters of the Torah. It follows that the features that identify a kosher fish also represent two qualities that are required of a Torah scholar, even when the “body” of his scholarship is undisputed.

The fish uses its fins to propel itself forward, quickly moving from one location to another. In the analogy, this represents the scholar’s obligation to expound upon the Torah knowledge that he has received from others, to discover new layers of Torah interpretation and novel approaches to its application.

But fins are only one of the requisite signs of a kosher fish; the kosher fish is also covered with a protective layer of scales. The Talmud (Shabbos 31a) compares the Fear of G-d to a preservative, without which one’s Torah study can spoil. Similarly, the protective scales that serve to identify a kosher fish represent the Fear of G-d that must accompany one’s Torah study.

This explains the spiritual significance of the Mishna’s statement that the presence of scales on a fish is an automatic proof that it is kosher, even though fins alone do not provide such proof. This is because, in the Mishna’s words (Niddah 9:6), “Every fish that has scales also has fins, though there are some fish that have fins but have no scales.” This means that Fear of G-d not only saves your Torah scholarship from spoilage and ensures that it will have the desired effects on your life; it also guarantees that you will ultimately make your own contribution to the chain of authentic Torah wisdom.

—Reshimos vol. 39