Is there any particular significance to the dietary laws as far as the story of Noach is concerned?
God orders Noach to take with him into the ark a sample of every species of animal so that it may survive the flood: "Of every pure animal you shall take seven pairs, males and mates, and of every animal that is not pure, two, a male and mate" (7:2). To what qualities do "pure" and "not pure" refer? Chazal, as cited by Rashi, explain that God here speaks of the dietary "kashrut" laws that will later be taught to Benei Yisrael. Interestingly, God in this verse assumes that Noach was familiar with these terms and would have no trouble identifying the "pure" and "not pure" animals. From here the sages conclude that Noach studied Torah. The knowledge of halakha he had attained allowed him to easily understand the Almighty's intent regarding the different types of animals.
Of course, there is much room for discussion as to what and how Noach studied, a topic well beyond the scope of this context. We will instead focus on a less complex but perhaps equally as important issue. Why would the Torah inform us of Noach's mastery of specifically this area of Torah law? In other words, is there any particular significance to the dietary laws as far as the story of Noach is concerned?
We may find our answer in the final verse in Parashat Shemini, where the Torah concludes its discussion of the laws of kashrut: "[These are the instructions… ] for distinguishing between the impure and the pure, between living things that may be eaten and the living things that may not be eaten" (Vayikra 11:47). Kashrut is about "distinguishing." It reflects our responsibility to set limits and exert control over our basic instincts, such that definite lines are drawn between the permissible and the forbidden, the acceptable and the objectionable. Noach's generation eliminated boundaries, rejected constraint and encouraged unfettered pursuit of one's desires. The Torah points to two sins in particular: unlimited sexual indulgence (6:1) and theft (6:11). Both point to mankind's refusal to erect barriers between that which is theirs and that which is denied to them. They showed no loyalty to spouses or to their fellow man, allowing themselves unrestrained access to all women and property. Noach, who opposed the prevailing lawlessness of his time, recognized the distinction between "pure" and "impure." He drew the necessary lines between that which he was allowed and denied; this was perhaps the most important "Torah" that he studied.
In the verse with which we opened our discussion, God refers to the pairs of animals to be brought onto the ark as "ish ve-ishto," which literally translates as, "husband and wife." The Gemara (Sanehdrin 108a) asks the obvious question, do animals and beasts marry? What is the meaning of "husband and wife" in the context of animals? The Gemara answers that Noach was to bring with him only those animals who remained loyal to their mates, who lived, in a certain sense, as husband and wife. Chazal here perhaps teach us that only such loyalty could protect the world from the floodwaters and grant it continuity. The world continues to exist only when boundaries are drawn between acceptable and unacceptable behavior, when mankind is prepared to bind itself to an ethical and moral code rather than allowing itself to act freely without constraints.