פּירוש אויף בראשית 7:2

הטהורה CLEAN—It means those cattle which will in future be permitted to Israel as clean; we thus learn that Noah studied the Torah.

מכל הבהמה הטהורה, “of all the pure mammals, etc;” according to Rash,i we can learn from this verse that Noach had studied the Torah. [from where else would he know which of the mammals are “pure” mammals. Ed.] If you were to counter that in the Talmud Zevachim 116, we find the question: “since when did there exist a difference between the pure and the impure mammals at that period,” and the answer given to this question is that indeed at that time there did not exist a difference,” [If so what does Rashi mean seeing that he was familiar with the section of the Talmud? Ed.] The answer given there is that all the animals which the ark accepted without delay were the species which had never been used as sacrifices for idols. The others were rejected by the ark. This still does not solve our question. On the contrary, it shows that seeing that Noach apparently had brought more than one pair of the impure animals to the ark he had been unaware that that species was going to be impure according to the Torah in the future!We therefore have to resort to a different answer; any category of mammal of which Noach knew that it mated only with members of its own species, was recognised by Noach as one that in the future would be categorised by the Torah as a “pure species,” fit as an offering to the Lord;”When the Talmud referred to some categories of mammals initially being rejected by the ark, this indicated to Noach that the “concept” of purity and impurity had to do with the manner in which these species conducted their mating practices. In the Torah, in the future, the concept of purity and impurity is repeatedly used in respect to incestuous relationships in the Book of Leviticus chapter 18,34 and 20,25. In those chapters the term “pure” and “impure,” refers to which of these animals may be used as food for members of the Jewish people. Seeing that Noach recognised which of these species were (to be) allowed as food, we can understand Rashi’s comment. [which incidentally is based also on a statement in Sanhedrin 118. Ed.] A different approach to the questions raised by our verse: the Talmud quoted in the tractate Zevachim did not deal with mammals, but with birds, so that the question raised referred only to how Noach could know which birds would qualify as the ones of which he was to take seven pairs each into the ark. Seeing that there are an innumerable number of “impure” birds, and even the written Torah had not revealed how to know which was which, the question of how Noach could know what even the written Torah did not reveal to us in Moses’ time was most appropriate. The Talmud’s answer that this was revealed to Noach when he watched what happened when the birds tried to enter the ark is therefore very reasonable. Noach had to rely on Divine guidance. The Talmud did not refer to the same problem concerning pure mammals, as there are only a small number of such, and Noach was familiar with the mating habits of these mammals. This led Rashi to conclude that Noach had foreknowledge of what the Torah would decree at some time in the future. Seeing that due to the fact that these species would be allowed as food, the dangers that unless there were multiple pairs of them in the ark, they might die out, make it plausible that the Torah ordered him to take seven pairs of each. [Eating of meat had been completely forbidden prior to the deluge. Ed.] Even though certain other non pure mammals serve as food for the gentiles, such as pigs, etc, the fact that these give birth to multiple young made it unlikely that they would die out even if only a single pair of them would be taken into the ark.ft npn, “take for yourself;” seven males and seven females each, so as to diminish the chances that they would die out. If any of the animals that were not considered as worth eating would die out this was a minor concern, as man would not miss that species. Seeing that the word שבעה, masculine for seven, was repeated by the Torah, led Noach to believe that he was meant to sacrifice some of these after surviving the flood.

מכל הבהמה הטהורה, “from all of the ritually pure domestic animals;” seeing that the Torah had not been given yet, and therefore there were no ritually impure domestic animals or creatures, Rashi understands the expression as referring to the domestic animals that would in the future be described as being ritually pure. We therefore learn that Noach had already studied Torah laws which had not yet been revealed publicly (B’reshit Rabbah, 40, based on Psalms 1,2) If so, why did the Talmud in tractate Zevachim folio 116 have to pose the question of how Noach knew, and to answer that the ritually pure animals came to the ark on their own, whereas Noach had to round up the others in order to bring them into the ark? According to the Talmud, Noach only recognised ritually pure animals after the event, not because he had learned the physical signs described in the Torah.
There is a third opinion according to which it became clear which animals had been ritually pure only after Noach offered some of these as offerings after having left the ark. This interpretation is also not logical as G–d had commanded him prior to entering the ark to take seven pairs each of the ritually pure animals into the ark, so that he must have known beforehand which animals to take. This is also what Rashi commented on chapter 8, verse 20. He had realised that the only reason he had been commanded to take seven pairs of the species concerned was in order to have these animals available after the deluge to serves as sacrifices. It would appear therefore that the statement that Noach had studied the Torah, must have referred to the instructions to take such ritually pure birds, (6,4) something which became clear to him when noting that these birds were monogamous, mating only with the same female. When he saw that the ark accepted more than one pair of certain animals, it became clear to him that the extra specimens must have been meant to serve as sacrifices as G–d considered them as ritually pure. “Studying Torah,” as mentioned by Rashi, must mean therefore that he learned Torah by keeping his eyes open and drawing the right conclusions. He had also noted that these animals had only kept company with members of their own species during the long months in the ark. This is most likely also the reason why, when the Torah wrote the details about the laws of chastity and forbidden sexual intercourse in Leviticus 18,23-24, it stated that Jews must not defile themselves through such animals.