Bar-Ilan University's Parashat Hashavua Study Center

Parashat Shemini 5768/ Parah/ March 29, 2008

Lectures on the weekly Torah reading by the faculty of Bar-Ilan University in Ramat Gan, Israel. A project of the Faculty of Jewish Studies, Paul and Helene Shulman Basic Jewish Studies Center, and the Office of the Campus Rabbi. Published on the Internet under the sponsorship of Bar-Ilan University's International Center for Jewish Identity. Prepared for Internet Publication by the Computer Center Staff at Bar-Ilan University. Inquiries and comments to: Dr. Isaac Gottlieb, Department of Bible,



Kashruth in the Modern World


Amos Rubin, Agronomist 


Giv’at Shmuel


The word kasher is defined as meaning good, fit, suitable. In the Bible this word occurs only once, when Esther says to Ahasuerus:  “and the proposal seems right (kasher) to Your Majesty” (Esther 8:5).  The Sages used this word to refer to things that were fitting in terms of the laws of the Torah:  “The entire day is appropriate for reading the megillah,” or “fit (kasher) for slaughter,” [1] or to indicate something that is ritually clean or pure, the opposite of kasher being terefah (an animal torn apart by other animals), unfit, or impure.

One of the subjects in Parashat Shemini concerns forbidden foods:

You shall not draw abomination upon yourselves through anything that swarms; you shall not make yourselves unclean therewith and thus become unclean.  For I the Lord am your G-d:  you shall sanctify yourselves and be holy, for I am holy (Lev. 11:43-44).  

Similarly in Parashat Re’eh:   “For you are a people consecrated to the Lord your G-d:  the Lord your G-d chose you from among all other peoples on earth to be His treasured people. You shall not eat anything abhorrent” (Deut. 14:2-4). 

The Torah uses clear and systematic zoological criteria to define which animals may be eaten. Of mammals, it says:   “and any other animal that has true hoofs which are cleft in two and brings up the cud – such you may eat” (Deut. 14:6); and of that which lives in water it says:  “These you may eat of all that live in water:   you may eat anything that has fins and scales.   But you may not eat anything that has no fins and scales; it is unclean for you” (Deut.   14:9).

Kosher Fowl

As for birds, it says:  “You may eat any clean bird.  The following you may not eat” (Deut. 14:11-12), which is followed by a list of twenty-one forbidden birds.   Since identifying the unclean birds is difficult, the gemara says (Hullin 42a):   “A tanna from the school of Ishmael said:  This is the animal you may eat – this teaches us that the Holy One, blessed be He, grabbed hold of each kind of animal and showed it to Moses, saying, ‘This you may eat and this you may not eat.’”  Among ritually clean birds there are three indicators of purity:  an extra claw, a crop, and a gizzard that can be pealed by hand.   The indicators for an unclean bird are described thus:  “If, when it is placed on a wire, it grabs on with two claws to one side and two to the other, or if it catches food in the air, then it is surely a raptor.” [2]

In recent times Rabbi Dr. Israel Meir Loewinger published thirty drawings of birds by Rabbi I. M. Cohen, author of Zivhei Cohen (Leghorn, 1832). [3]   Rabbi I. M. Cohen made talented drawings of birds that in his day were thought to be kosher, marking down their Latin names.  To these drawings Rabbi Lewinger added photographs of 39 flying creatures of our day, including grasshoppers, birds and mammals. [4]


After the list of unclean birds in Deuteronomy, it says:  “All winged swarming things are unclean for you:  they may not be eaten” (Deut. 14:19). Regarding unclean insects Rashi says:  Winged swarming things are the lowly creatures that move upon the ground:   flies, hornets and unclean species of grasshoppers are called sheretz (=swarming things).”   Ibn Ezra (on Deut. 14:20) says:  Of all clean winged things – such as locusts” (which are mentioned in this week’s reading).  Hizkuni’s understanding is:  “According to the plain sense, including the pure varieties of grasshoppers, which are not mentioned here.”  These are the four sorts of insects that are included in the category of winged swarming things which may be eaten, as listed in this week’s reading:  “Of these you may eat the following: locusts of every variety; all varieties of bald locust; crickets of every variety; and all varieties of grasshopper” (Lev. 11:22).

The indication for kosher grasshoppers is:   “all that have, above their feet, jointed legs to leap with on the ground” (Lev. 11:21).   The gemara (Hullin 65a) adds to the four types of clean grasshoppers mentioned in Scripture the tzipporet keramim, yokna yerushalmit, artzuvya and razvanit.   This list also includes the names of locust larvae.  “the clean grasshopper has four front legs and four wings, covering most of the length and most of the circumference of its body, and it has two legs for jumping” (Lewinger, p. 222).   Although, “Abimi son of Rabbi Abahu said there were eight hundred sorts of grasshoppers” (Hullin, loc. sit.), Prof. Lev Fischelson has found that in Israel there are around 120 sorts of grasshoppers.  Lewinger notes (p.223):   “Locusts are the only variety for which there is a tradition permitting them to be eaten.”  In 1981 I brought a Schistocerca greagaria Forsk (desert locust) from the laboratory of Professor Meir Penner at the Hebrew University to Rabbi Joseph Kapah (1917-2000; Israel Prize laureate), and Rabbi Kapah confirmed identification of the desert locust as edible according to the tradition of the Yemenite Jews. [5]

As with grasshoppers, so is the case with eight forbidden sheratzim (crawling creatures) listed in this week’s reading alone (Lev. 11:29-30).   Thus, we see that the list of animals given in Deuteronomy is less extensive than the list in Leviticus, and does not include certain grasshoppers which may be eaten and other crawling creatures that it is forbidden to eat.

The Torah summarizes the subject of ritually pure animals thus:  “You shall not eat anything that has died a natural death; give it to the stranger in your community to eat, or you may sell it to a foreigner.  For you are a people consecrated to the Lord your G-d” (Deut. 14:21).

Pork: Why Not?

Of all animals, the pig is considered especially repulsive:  “also the swine – for although it has true hoofs, it does not bring up the cud – is unclean for you.  You shall not eat of their flesh or touch their carcasses” (Deut. 14:8).  The anthropologist Mary Douglass ascribes the general dislike of the swine to the biblical explanation: [6] According to the approach taken by cognitive psychology the swine creates confusion between clean and unclean animals because it has one of the indicators of clean animals, namely cloven hoofs, and one of the indicators of unclean ones, namely that it does not chew its cud.  Eating pork is considered an abomination:  “who eat the flesh of swine, with broth of unclean things in their bowls” (Isaiah 65:4, also 66:3, 17).

Is the logic of dividing all creatures in the world into the categories of pure and impure intended to cope with the powerful contradictory emotions in human beings?  An original view on this was voiced by Dr. Avshalom Elizur (Bar Ilan University):   “This is a possible point of departure for a psychoanalytic explanation why the swine is hated; namely, that it is similar to human beings in certain respects, like the hatred between Israel and Amalek, who are of common origin.” [7] Heinrich Mendelsohn [8] mentioned in a lecture of his that the structure of teeth in human beings is similar to that of pigs, and that both these creatures are omnivores (eating meat, plants, and fruit).  It is well-known that today the skin, pancreas, and valves of pigs are used for implants in humans.  It is interesting that even in the time of the gemara, some 1500 years ago, the Sages knew about the similarity between humans and pigs, as it says in Ta’anit (21b):

They said to Rav Judah:   There is an epidemic among the pigs, and he   proclaimed a fast.   Shall we assume that Rav Judah thought:   A disease that affects one kind of creature, can affect all kinds?  No; for pigs are different, since their guts are similar to the guts of human beings.

Rashi’s commentary on this explains:   “The guts of pigs do not have an inner stomach, like other animals; and it is a bad sign.”

The gemara uses a euphemism to refer to pork (Shabbat 129b) and compares those who raise pigs to those who are usurers (Berakhot 58a).  Commenting on the mishnah in Tractate Bava Kama (7.7), “Swine should not be raised anywhere,” the gemara (82b) says:

When the Hasmoneans were laying siege to one another, Hyrcanus was within and Aristobulus without.  Every day they would deposit some coins into their box, and they would give them sacrifices for daily offerings.  There was a certain elder there, conversant in Greek philosophy, who said to them:  as long as they are busy worshipping, they will not be delivered into your hands.   The next day they deposited money into their box and gave them a pig to sacrifice.  When it came half way up the wall, it sunk its claws into the wall, and the land of Israel quaked over an area of 400 parsa by 400 parsa.  It was then that they said:  cursed is the man who raises swine.

Maimonides: Two Explanations

Maimonides wrote (Guide for the Perplexed, Part III, 48):

The flesh of swine is more moist than is fitting and has much waste.  The Torah finds swine repulsive principally due to their great filthiness and the fact that they live on refuse.  The Torah forbade the sight of contamination even in the encampment in the wilderness, and all the more so in cities.  Were pork to be eaten, the marketplaces and even the houses would be more filthy than lavatories, as one observes these days in the lands of the Franks (western Europe).   Blood and animals that have died a natural death, as well, are hard on the digestion and are poor food.   It is well known that animals which end up as nevelah start out as terefah.

In Eight Chapters (Shmoneh Perakim, introduction to Ethics of the Fathers) however, Maimonides cites Rabbi Eliezer ben Azariah:  “Whence do we know that a person should not say that it is impossible … to eat pork… It is possible, but what can I do if my Father in Heaven decreed that I should not?” (Sifra, Kedoshim, 10).  A substitute for it was even given in the form of fish:  Shibuta is similar to pork” (Hullin 109a).  The sources here do not associate the prohibition to eat pork with any revulsion or an emotional factor.  One could indeed desire to eat pork, but the Torah forbids it for spiritual reasons:  “for distinguishing between the unclean and the clean” (Lev. 11:47).

The Health Factor

The parasitologist Prof. Gideon Wittenberg writes, “Swine carry trichinosis, caused by Trichinella spiralis.   These adult nematode worms produce as many as 1500 tiny larvae, 0.1 mm long, which lodge as parasites in the intestines and voluntary muscles of swine; humans can be come infested by eating pork.   In the Middle Ages 15% of the population died in epidemics of digestive disorders and muscle poisoning, and the Jews, who did not eat pork and hence did not become infected, unfortunately were accused by the Christians of having poisoned them.”

Modern studies confirm that the disease, caused primarily by eating the flesh of wild boars, is fairly rare today in most countries of the world, and in the United States there are only around 100 cases per year. [9]   The Department of Epidemiology in the Ministry of Health in Israel lists trichinosis among the 70 diseases which must be reported. Dr. Etty Maro, from the public health laboratories in Jerusalem, informed me that between 1998 and 2004 there were 10 outbreaks of the disease among 200 Thais who hunted wild boars or purchased them from hunters.   Until 1997, only Christian Arabs and a few hunters had been affected by the disease.  From 2004 to 2006 there were another three outbreaks of the disease among some 20-40 people, who had to be hospitalized.

Marvin Harris, an anthropologist, explains that Israel, being an arid country, is not appropriate for raising hogs since this animal does not have sweat glands and consequently needs to cool off in sources of water, which are in short supply in the land; hence the prohibition in ancient times against raising hogs here. [10]   This explanation, however, does not account for the sense of repulsion that Jews developed towards the swine.  

Pig Out, Pig In

Radbaz, and following him Rabbi Hayyim ben Atar (1696-1743), in his commentary on the Torah, Or ha-Hayyim, cites the following midrash with regard to the verses on this in this week’s reading:  “why was it called a hazir (=swine)?  Because in time to come the Holy One, blessed be He, will restore it (le-ha-haziro), making it permissible to be eaten.”


[1] Megillah 2, 8; Hullin 1, 4.

[2] Shulkhan Arukh, Yoreh De’ah, 82, 2.

[3] Sinai 64, pp. 258-281.

[4] See Loewinger’s book, Kosher Food from the Living (Hebrew), Jerusalem, 1978.

[5] See his book Halikhot Teiman, Jerusalem: Yad Ben Zvi, 1978.

[6] Mary Douglass, Purity and Danger, an Analysis of Concepts of Pollution and Taboo. New York: Frederick A. Praeger, 1966


[7] See his article at

[8] Personal communication. Mendelsohn (1910-2002) was Professor of Zoology at Tel Aviv University and recipient of the Israel Prize.

[9] D. Despommier, R Gwadz, P. Hotez & C. Knirsch, Parasitic Diseases, 5th edition, New York, 2005.