A kosher animal can be distinguished by two signs: completely split hoofs and chewing its cuds. Animals with one characteristic but not the other are specifically excluded. The hoof must be completely split, so that there is a crack running through the hoof from front to back. For example, a rabbit has a split in the front but not in the the back of its foot and is not kosher.
The Lubavitcher Rebbe offered a homiletic explanation.
The hoof must be split entirely, from the top to the very bottom. The hoof is divided into two, to indicate that our walking on this earth, i.e., our mundane involvements, must include two basic principles: drawing near to oneself that which is good and proper and pushing away that which is not.
But the sign of a split hoof by itself is not sufficient. There must also be the sign of chewing the cud.
One must very carefully "chew over" every mundane activity which one intends to undertake. One must clarify and determine, once and again, whether to do it altogether, and if so, how to do it. Only then will the action itself be a "pure animal" - something which can and is used for our spiritual mission in life.
The distinction between "right" and "left" is very important. One cannot hope to obtain goodness without shunning evil. Good and evil must never be confused, just as the kosher animal's hooves are split into two distinct halves.
The second characteristic of a kosher animal is that it chews its cud. Likewise, a Jew must "chew over" his every step and consider it carefully before acting. When we subject our behavior to this scrutiny, all our actions will be pure ( I combined different versions).
It seems to me that one can explain these "signs" as representing the two activities that must occupy a servant of Hashem: Birur and Tikkun. Hoofs represent our lower activity - distinguishing good form evil, grasping the former and rejecting the latter. In this regard, evil and good must be completely separated in our minds and our actions. Confusion or uncertainty as to what is good and what is evil is a rabbit's foot and such an animal is not kosher. However, this is not enough. Pig possesses a fully split hoof but is still not kosher. What is important is what one does to elevate the good that is accomplished to a higher level.Chewing the cud is the process of return and elevating.
Chewing the cud represents the repeated steps of return, refinement and purification that follows Birur. As one rises in spiritual stature, there must be a continued process of review. Each accomplishment must be grasped and raised to a yet higher level and the levels of Tikun are infinite.
This means that at the time of the exile of the Shechinah ...at this time the main spiritual task of man, and the main purpose of being engaged in Torah and the commandments, is to disencumber and elevate the sparks, as is known from the teachings of R. Isaac Luria, of blessed memory...
But when the Shechinah will emerge from kelipat nogah after the extraction of the sparks will be completed, and the evil of the kelipot will be separated from the good of holiness, “and all the workers of evil will be dispersed,” then people will engage in the study of Torah and in the observance of the commandments not in order to extract the sparks, as in the present, but in order to bring about the consummation of yichudim (“unions” or “marriages” of Sefirot) more sublime than those which are effected through our present Torah study —in order to call forth more sublime lights, transcending Atzilut.
This is why the pig is not kosher at this time for it forever is destined to stay on the ground. After the Messianic revelation, when the work of separating good and evil ends, however, it will also be able to rise and become kosher.
Knowing what is good and what is bad without attempting to elevate the good is not enough. Not only is it not enough it is deceptive.
And Cain went out... Whence did he go out? Rabbi Aibu said: "It means that he threw the words behind him and went out, like one who would deceive the Almighty." Rabbi Berekiah said in Rabbi Eleazar's name: "He went forth like one who shows the cloven hoof, like one who deceives his Creator." (Midrash Rabbah Genesis 22:13)
Esau is a pig and so also does Western Civilization recognize and delineate clearly what is good and what is not.
Rabbi Isaac said: "[God declared]: 'You have given a name to your swine [Esau]; then I too will name My firstborn, as it says, Thus says the Lord: Israel is My son, My firstborn'" (Midrash Rabbah - Genesis 63:8)
Why does he compare it [the Roman State] to a swine? For this reason: when the swine is lying down it puts out its hoofs, as if to say, "I am clean," so does this wicked State rob and oppress, yet pretend to be executing justice. So for forty years Esau used to ensnare married women and violate them, yet when he attained forty years he compared himself to his father, saying, "As my father was forty years old when he married, so I will marry at the age of forty." (Midrash Rabbah - Genesis 65:1).
Why is it [i.e. Edom or Rome] compared to a swine? To tell you this: Just as the swine, when reclining, puts forth its hooves as if to say, 'See that I am clean,' so too does the empire of Edom [Rome] boast as it commits violence and robbery, under the guise of establishing a judicial tribunal. This may be compared to a governor who put to death the thieves, adulterers, and sorcerers. He leaned over to an advisor and said: 'I myself did these three things in one night.'" (Midrash Rabbah - Leviticus 13:5)
Unlike Ishmael, for whom the good and the bad remain inextricably confused, for whom violence and worship of God are linked and intertwined, Esau has used philosophy and sciences to clearly delineate the borders of moral behavior (even if he does not always agree with us on where to place these borders), However, he does not aspire to go beyond this-earthly abode and to raise the good to Heaven.
A number of authorities, including Rav Menachim Azarya DeFano, Rav Chaim Ibn Attar, and the Chatam Sofer, suggested that the pig will undergo what may be called an evolutionary process and develop a cud, rendering it kosher! I suggest that this means that after Moshaich comes Esau will also learn how to elevate the good.




